In our week-long IXP dataset, we observe some 28K server IPs for Akamai in 278 ASes (for details, see Section 5).

akamai publicly states that it operates some 100K servers in more than 1K ASes [15].


If we cut o. testing too early, Virgil may not .nd all usable access points.

if the delay Virgil imposes is burdensome to users, they will abandon our system.


In on-demand wake-up schemes [16][17], often a two-radio architecture is deployed where a second low power radio is used to detect the presence of nodes, and this low power radio will activate a high power radio on demand for packet delivery.

on-demand schemes are not suitable for DTNs since the lower power radio often does not have enough transmission and reception ranges to allow nodes that are sparsely distributed to discover one another.


In the transmission scheduling scheme used for lower bound construction, it su.ces for a node to always transmit on a speci.c channel without requiring to switch channels for different packets (recall that the same mini-slot on a speci.c channel is used by a node in all edge-color slots).

a node may have to switch channels for receiving data.


(When TCP is in the slow-start phase, it sends two packets for one ACK.)


In case of the best effort class, the bandwidth manager uses the median of the utilization distribution, denoted by Median(&), as an estimate of the bandwidth requirement (this is because requests in this class desire low average response times).

a high percentile of the utilization, denoted by Perc(U,t), is used to estimate the requirements of the real-time class (since the tail of the distribution better reflects the needs of real-time requests).


The high AI concentration activates the production of more LasR and LasI through the two feedback loops, shown in Fig.2 (b), and therefore generates more virulence (see Fig.3 (b)).

in the 100 cells case, the AI concentration does not reach the activation threshold and therefore it does not cause any infection.


Furthermore, an excess deployment might seriously deteriorate the stealth character of the system.

a partial coverage problem can be reformulated as a full coverage problem.


[9] both reduce the memory imbalance by using variable strides to minimize the largest trie level.

even with their schemes, the size of the memory of di.erent stages can have a large variation.


2.2 Public Key Cryptography (PKC) based Encryption Traditionally wired computer communication networks have used Public Key Cryptography (PKC) as a means of secure communications since they provide the most secure form of communication available today.


Consequently, in our implementation, the initial search window (tmin,tmax ) is set to (40, 100).

once the periodicity of the person s walk is found to be topt, the search window is reduced to a few samples around topt.


The positive sensing contribution, comprised of peaks (dark areas in a sea of white) tends to increase the probability of an event taking place near the peak.

the negative sensing contribution is comprised of troughs (white depressions in a plateau of dark) that decrease the probability that an event happened in the recess by increasing the probability everywhere else.


4, and the complete sets of AS algorithm, as expected, the aggregation latency is larger with smaller a, which represents less path loss of power and thus larger interference from neighbor nodes, and larger ß, corresponding to higher SINR requirement.

simi lar latency performance is observed with NN-AS, at di.erent values of a and ß.


The mesh backhaul uses an orthogonal frequency band (900 MHz) to avoid interference with the traf.c sources being monitored.

this gives rise to a related challenge in that wireless mesh networks are typically very bandwidth-constrained, and the total amount of traf.c being captured by a set of sniffers may exceed the capacity of the mesh.


4It is not, in general, possible to reduce a path measurement into one or more single point measurements without additional data plane state to record trajectory information.

it is possible in this simple experiment.


For a small number of seekers (i.e., p(s) = 0.2), the optimal and greedy policies basically coincide, as for such a small percentage of seekers the overall computational capacity of the system is large enough to a.ord greedy replication.

when the number of seekers increases beyond this point, the greedy policy saturates the system.


Other papers propose a joint use of these techniques [6, 9] or a cross-layer approach [12, 15].

none of such approaches proposed for wireless ad hoc or sensor networks exploited the possibility to turn o. some radios on multiradio devices.


The data shown refers to a trace collected from the passive measurement system on July 24th 2001.

we have systematically observed similar delay distributions on all the traces collected in the Sprint monitoring project [13].


Tarzan s discovery protocol propagates knowledge the same as Name-Dropper [16].

for nodes with neighbor lists of size within a constant factor, node awill only transmit to node bthose neighbors not previously known to b.


Second, because the CA component is part of the protocol it has access to the protocol s node state and information exchanged among protocol peers.

there is a single CS component per MAC protocol that interacts with all CA components at the network layer.


In matchmaking [1], game players selects low delay opponents according to Toread s RTT estimations instead of bruteforce measurements or random.

2) Finding Detours: game players not only care about lag, but also prefer playing with with opponents in the same level.


The necessity of signaling synergy is partly driven by the requirement for carrier-gradevoice support, partly by inter-system switching in hybrid 3G/4Gdeployments, and partly by mobility management.

interactions among signaling protocols are not always designed and operated right: (S1) a user device is temporarily out of service becauseits vital context in 4G is shared but not well protected (being deletedafter inter-system switching); (S2) Users are denied network accessright after being accepted because higher-layer protocols make unrealistic assumptions on lower layers; (S3) 4G users get stuck in3G because inconsistent policies are used for CS and PS domainsin 3G and 4G.


Thus, estimating the number of uncaptured beacon frames is a non-trivial problem and needs future investigation.

based on the uncaptured frame percentage values for large DATA frames shown in Table 1, we believe that the loss of short beacon frames will be comparatively smaller.


In switch scheduling, the scheduler knows the instantaneous state information of each input/output port, and can compute the schedule for each packet transmission.

tWIN has to deal with network scheduling where signi.cant propagation delays may exist among sources and destinations.


A protocol that has access to full membership selects gossip targets at random from the entire population.

maintaining full membership is impractical in large-scale settings.


in 7 out of the 10 .ows it receives substantially lower throughput than AMCP and .ows 6 and 7 receive very low throughput similar to 802.11.


At best, idle devices can keep track of the agreements that others make.

this information becomes stale once the devices become busy.


There is no need for human intervention (as in the manual solutions).

the RIC solution may have some shortcomings.


As an example, consider a solution in which there is a way-point that is far-away from the rest of the points, and is chosen because a small amount of waiting at that way-point contributes signi.cantly to contact probability.

the additional time required by the ferry to travel to such a way-point may negate the advantage.


Note that that revealing f(N)enables anyone to immediately compute the RSA private key d = e -1 (mod f(N)) from the RSA public key (e, N ).

both the standard DSS signatures and BLS signatures of [4] are based on variants of the discrete logarithm problem where all the moduli used in computations involving secret shares can be made public.


Using simple simulations, we have shownthat CompoundTCP+ connectionshavehighfairness in wireless LANs.

in our previous work, we have not examined the congestion control scheme of Compound TCP+, and the performance of Compound TCP+ has been evaluated onlyby meansof simple simulations.


Within an application cycle, the offset of a frame may vary from period to period.

a particular TTEthernet implementation may restrict the sending times such that the offset of a frame is identical in all the periods (which has the advantage of reducing the size needed to store the schedules).


Reducing false positives: We have focused on accurate detection of signi.cant deviation from normal behavior.


deconstructed the source code of the Witty worm to estimate various properties about Internet hosts (e.g., host uptime) as well as about the propagation of the worm itself (e.g., who infected whom) [14].

our work explores the behavior of spammers in depth, although we also peripherally study malware whose exclusive purpose is to send spam (i.e., the Bobax drone).


Feasibility determination of any demand allocation is a NP-complete problem even if global slot synchronization and topology knowledge are available [21].

in practice, the link demand changes will be due to end-to-end bandwidth allocation or hand-off mechanisms running locally at the nodes.


4.1 The Big Picture The Internet s energy use is small compared with the 16 TW consumed globally [5].

transportation uses 61% of global oil production [1].


We observe from (5) and (6) that when the number of cooperative sensors for spectrum sensing, n (or |G|), increases, then the cooperative detection probability Qd of the group increases and as a result the accuracy of primary user being detected also increases.

the higher |G|, the higher cooperative false alarm probability Qf which in turn leads to a higher chance that a spectrum opportunity will be missed.


At Layer 3, the number of required forwarding table entries shrinks substantially and is easily accommodated in switch hardware.

address assignment now requires centralized and error prone manual con.guration [3, 13, 14], e.g., con.guring DHCP servers and assigning subnet masks to each switch.


This condition is invariable up to N users.

the BER performance of POCI code degrades as the  code an d t h e p r oposed code  [5] A.


It is a new version of the SUIF compiler system, a free infrastructure designed to support collaborative research in optimizing and parallelizing compilers.

since SUIF-2 was not developed for NesC language (the language used by TinyOS), a number of constraints and structures are not supported by SUIF-2.


So, multicast data transmission is achieved exactly as a unicast data transmission.

unlike QOLSR protocol, multicast packets can be retransmitted by destinations (overlay nodes).


This would clearly be a serious infringement on privacy.

for such a scheme to be e.ective, there are several technical challenges: For a speci.c targeted individual such as Bob Smith, 28 years old, living in Kaiserslautern Germany can Alice determine with certainty his VoIP ID?


The reason is the fact that it employs a big percentage of nodes in order to forward the data, since the packets are routed through alternative paths in case of congestion.

when Sen-TCP is employed, the average node energy consumption is less, since there are many nodes which remain in full power, due to the fact that Sen-TCP always uses the shortest path to forward data.


We deliberately keep these points very generic in order to make them applicable to many different mobility models.

there are certain prerequisites for a model in order to make the SO applicable.


Our goal is to bene.t from the increased routing progress of speci.c bursty links.

we do not want to deteriorate the stability and reliability of wireless routing.


The IPv6-capable percentage actually decreased slightly.

this decrease was caused by a decline in 6to4 connections, while the percentage of native IPv6 connections increased very slightly.


Consequently, this investigation can focus on forwarding, and not on route .nding.

it should be emphasized that we make no claim that the behavior displayed in Figure 1 is typical for changing modulation and codes.


0.5 second), and this type is used in proactive routing protocols such as Destination Sequence Distance Vector (DSDV) and Wireless Routing Protocol (WRP).

the second is to send it only when a node requires sending a packet.


The specification of Tmote-sky says that the radio range is up to 50m.

it has been found that after 16m, the packet drop percentage reduces considerably [23].


We note that, when considering a small timeslot duration as in Figure 5, decreasing the value of a results in a predicted harvested energy less similar to the current harvested energy, due to the high correlation between subsequent updates of the actual harvested energy.

a small value of a can be seen as a pragmatic way to capture the uncertainty in determining on-the-.y the actual amount of energy that will be harvested by the node.


The methods above are prone to errors due to non linearity in the relation between distance and signal strength and/or to the relevant cost of maintenance and environmental calibration[1 5].

they are widely usedin commercial solutions because they only require software-based solutions in o.-the-shelf WLAN devices.


we found the naive approach of replacing 2D convex hulls with 3D convex hulls to be impractical.


While connectivity among clusters allows the ferry to visit a subset of nodes in clusters, customized ferry routes can lead to substantial improvement in performance, e.g., higher delivery ratio and lower delay.

intra-cluster tra.c can cause severe interference to data exchange between the ferry and gateways.


Multicasting in the Internet and mobile ad hoc networks (MANETs) has been studied extensively in the past [3, 6, 7, 8, 15, 16, 18].

due to the unique characteristic of frequent partitioning in DTNs, multicasting in DTNs is a considerably different and challenging problem.


Compared with exact-match rules, wildcard rules improve the reusability of rules in the .ow table and reduce the number of .ow setup requests to the controller, enhancing the scalability of the system.

wildcard rules are typically supported by Ternary Content Addressable Memory (TCAM), which is highly limited in capacity.


Therefore, to achieve this time coordination among nodes, a number of centralised time synchronisation algorithms have beenproposed thatareoptimised for low-powerwirelessnetworks [5].

they are not suitable for DCM networks because of issuespertaining to maintenance overheads, synchronisation delays, and single points of failure [6].


Gk increases), the higher is his profit from getting attached to that network, and therefore the value of his JCDMA,k value increases.

as WLAN effective capacity increases, WLAN becomes more advantageous for the new user to be attached to, and therefore the corresponding values of user s normalized profit per resource unit under CDMA and WLAN networks steer him to prefer WLAN after an achieved Cmax (Fig.2).


The use of broadcast is natural for a game with three or more players as only one send() is required for each data 1 0.75 0.75 Cumulative Distribution  Cumulative Distribution 0.5 0.5 0.25 0.25 0 0 0 100 200 300 400 500 600 Frame Size (bytes) Frame Size (bytes) (a) Nintendo DS(b) Sony PSP Figure 5: Frame Size Comparison for Di.erent Games Platform Game Percent   PictoChat 1% Metroid 10%DS Super Mario 3% Ridge Racer 10% Soccer 6% Need for Speed 8%PSP Legends 96% Golf 98% Table 3: Percentage of Frames Sent by Broadcast packet sent, while directly addressable frames need a separate send() for every other player.

the side e.ect of broadcast is that the data is received not only by all other game players, but by all other computers on the same 802.11 channel.


It is a delay-probing TCP representative.

tCP Cubic and TCP New Reno do react positively to PFC.


The black node is the one de.ning the logical neighborhood, and its physical neighborhood (i.e., nodes lying in its direct communication range) is denoted by the dashed circle.

the dark nodes are those satisfying the predicate in the neighborhood template HighTempSensors when the threshold is set to 100o C. the nodes included in the actual neighborhood instance htsn100 are only those lying within 2 hops from the sending node, as speci.ed through the hops clause during instantiation.


For strategies which use a constant device discovery interval, the larger the probing interval, the larger the missed opportunities and viceversa.

in stochastic environments, device discovery should be done adaptively by choosing the probing interval based on the state of the environment.


Therefore, dynamic address assignment is not a problem for measuring the length of sessions.

it can become problematic for measuring the gap between sessions or correlations across consecutive sessions.


This is shown in Figure 1(a), where the Ethernet peer contributes 1600Kbps to the overlay.

if peers contribute only as much as they receive (the Bit-for-Bit semantic), then the Ethernet peer contributes just 400Kbps as shown in Figure 1(b).


This allows us to deploy Kademlia-like algorithm [6] for the routing protocol.

dHT only provides us part of the solution as there are still challenges we need to overcome in order to build a DHT-based routing protocol.


1 South North Brunswick, NJ 08902 shuchen@cs.rutgers.edu; yu, trappe@winlab.rutgers.edu ABSTRACT Wireless sensor networks are typically deployed to measure the information .eld, rather than create an information .eld.

by utilizing the radio on sensor nodes, it is possible to invert the role of sensor networks, and allow sensor nodes to actuate the environment.


MSCR/CS reduces the server download ratio by 13.7 compared to the original MSCR.

the amount of tier-1 tra.c slightly increases.


Thus, the size of regions for POIs should not be large.

if the size of a demand source region is small, it will be di.cult to aggregate multiple demands from di.erent vehicles at di.erent positions in the region.


According to an analysis of the estimated clustering coef.cient with respect to the vehicle density (see Figure 2), for lower densities, the clustering coef.cient is also low, but the variability is high.

when the density is high, also is the value for the estimated clustering coef.cient, but the variability is low.


We then drafted a number of scenarios unlikely to occur in a normal network and built BAFFLE, 4 a generator 3The authors also note the use of vendor-speci.c information elements in beacons and point out that these can be used to identify the manufacturer of the AP.


Most of today s network services are built on the IPv4 network.

iPv4 architecture has a serious problem caused by IPv4 global address exhaustion.


This argument doesn t carry much weight as long as links are truly underloaded.

one point to note is that a link that is loaded at 15% on average may still exhibit high queueing delays for short periods, and that these may be long enough to impact voice quality.


Figure 2.b shows the network topology collected by traceroute where P1 and P2 are two paths between A and D and P3 is a single path between B and C. Based on this topology map one would infer that the use of P1 for A to D path along with the use of P3 for B and C path would satisfy the node and link disjointness requirement.

this would be an inaccurate conclusion as routers R2,R4,R5 and R8 are sharing a multi-access link and P1 and P3 are not really link disjoint.


Therefore, in a recent development, the FCC is investigating the use of Caller-ID spoo.ng for fraudulent purposes.

since Cell2Notify does not attempt any fraudulent activity, we do not expect it to be affected in the near future.


To provide the .exible but assured di.erentiation at the .ow granularity, the best IntServ designs employ such complicatedlink scheduling algorithms asWFQ(Weighted Fair Queuing) [9], WF2Q (Worst-case Fair Weighted Fair Queueing) [2], Start-time Fair Queueing (SFQ) [20], VirtualClock(VC)[40], orEarliestDeadlineFirst(EDF)[10] and restrict network access with distributed admission control [17, 28].

rD routers maintain only two FIFO queues per output link and schedule the link capacity with the simple algorithm which is easy to implement even at high bitrates.


However, this approach requires lot of processing and consumes lot of resources, thus presenting a deployment limitation.

employing symmetric cryptography using a secret (key) shared by ad hoc nodes is a simple approach in terms of requiring lesser processing and consuming lesser resources.


Theoretically, d-median whose objective function aims to minimize the overall delay, yields smaller average delay in every case.

there are some points in graph where set covering yields smaller average delay.


from wireless to wired), the unfairness problem as shown in Figure 5 is not as serious as for the MIXED traffic case.


Tuning ARED to maintain a target_delay and control_interval similar to that used by CoDel and PIE will lead to similar results.

the lesson the community has learned with RED is that an AQM algorithm must not require configuration tuning that might be specific for particular workloads or environments [14].


This makes it di.cult to design a single content-based extension that can satisfy the needs of all businesses in this industry.

even companies having vastly di.erent businesses may .nd it useful to use a speci.c DRM functionality, e.g., authentication, negotiation services, etc., particularly if it can be easily integrated into their existing infrastructures.


We had presented the results when the scheme was used with synthetic tra.c with low variability white space distributions (for which Squared Coe.cient of Variation (CoV 2) is less than 1.0) such as 2-Erlang and Uniform distribution.

from our simulation experiments, we found that the channel occupancy data (idle and busy time values) for real primary applications show high variability.


Compared with various parts of message we need to mask during template learning, the number of location format patterns are limited, which is manageable for extraction using prede.ned patterns.

the naive pattern matching is not suf.cient to extract needed location addresses, mainly because more than one location pattern (no matter whether they are all needed) can be found in each message.


It was concluded that at 24 Mbps (i.e., 16-QAM with ½ coding rate), the system would experience the lowest probability of collision in the channel.

we feel the question remains open for the following reasons: Only one communications scenario, with low overall channel load, was evaluated.


INTRODUCTION Dense deployment of sensor nodes which have been spread randomly is the most practical and preferred way of deployment in many circumstances.

it causes that some area of the sensor field to be covered by too many nodes, and some regions of the monitored area might suffer from poor coverage.


Anotherimportant intuitionthat canbegained fromthose .guresisthat bothperformanceindicesincreasewiththe numberof users.

this is an effect of the increased multiuser diversity: the greaterthenumberofUEs,thehighertheprobabilitythatfor each subchannelthereisatleast oneofthemwithagoodCQI.thisincreaseissigni.cant only whenthe numberof usersislow.


Various channels di.er in their statistical quality.


Multpath routing and fake message injection are introduced in [3] to provide receiver privacy.

it concentrates on the tra.c-analysis attack, which determines the location of the sink through the measurement of tra.c rates at various locations.


Accordingly, we use the systolic width, denoted by wsys, and the diastolic width(wdias)as separate input parameters.

the amplitude is assumed to be equal for both the phases, and is represented by a single amplitude parameter amp.


Thus, if the channel idle detection delay is also negligible, CSMA should provide almost 100% utilization of the o.ered load of the channel.

in practice, the utilization is much less due to the latency in the idle channel detection at the MAC layer.


We can see, in Figure 17, how this inaccurate estimate directly contributes to localization error as the DOI increases.

the DV-Hop scheme estimates HopSize using online information exchanged between anchors.


It is impossible to make the di.erence between normal activity and attacks/problems in the way they manifest themselves in this type of alerts by looking at the individual alerts.

we believe that the distinction can be made by analyzing the aggregated alert .ow, and especially its intensity, the number of alerts in a time unit with respect to recent history.


To make the model more realistic, these times should have followed some probabilistic distribution, something that we are able to model as we already presented in [12].

to make the simulations the least random possible, we decided to set these times as 1 in order to compare the di.erent protocols in the di.erent simulations in a fair way.


di.erent models and richer visualization features.

the engineering e.ort required for such a move (di.erent APIs, abstraction levels, models, etc.)


It can determine its maximal wireless coverage region M W B  by taking the union of all circles of radius R cen- Wtered in , and its assured wireless coverage region EAB B these assumptions, a na¨ive, but intuitive constraint is: if A hears B taking the intersection of circles of radius r. then A must be within transmission range of B.

if A doesn t hear B then A must be outside transmission range of B.


After receiving the queries, the data sources will send data to the sink by the reverse path.

in the TTDD scheme, each node should acquire the location information by GPS devices for constructing the grid structure, while our cluster-based scheme does not need any location information and, hence, can prevent each sensor node from the cost of equipping the GPS device.


Si = M axGw (12) i.GW  3.5 A fast suboptimal solution The proposal of this paper provides an optimal solution considering a whole set of movements snapshots for an area.

the solution of this model can become infeasible to be obtained by an optimization solver depending on the range of the values of the data and depending on the number of variables and constraints that it has.


The plot shows that as expected the BER increases as the distance between the two antennas reduces.

the BER does not see a signi.cant increase until the antenna separation is less than 0.2 half-wavelengths (0.18 feet).


The same experimental traf.c pro.le was then run using the Fort-NOX controller where we varied the experiment by evaluating the same 1000 candidate .ow rule insertions.

this time we pre-seeded the FortNOX aggregate .ow table with 1, 10, 100, 500, and 1000, unique resident .ow rules, against which the set of 1000 candidate .ows were evaluated for con.icts.


Proposals such as VoC-CN [16, 17] try to support online live streaming and group communication over NDN architecture.

such systems might incur signi.cant overhead due to the inherent query/response communication model, when a simple pub/sub form of information dissemination is desired.


The dis- tribution of the average bandwidth of Gnutella hosts is similar to that of FastTrack hosts and is not shown here.

we observe higher bandwidths (both upstream and downstream) for the DirectConnect hosts in Figure 9(b).


INTRODUCTION The research of QoS gurantee problem in ad hoc network begins in the 1990s, and has gradually become a hot issue of research in ad hoc network.

dynamic features of ad hoc networks make it very difficult to support QoS.


In our proposed MAC protocols we assume symmetric channel support (i.e., if a channel is supported then it is supported for both reception and transmission).

minor extensions to the protocols can be made to provide asymmetric channel support.


The system relies on DC-nets and veri.able shu.es, and cleverly exploits its infrastructure based architecture to scale to hundreds of clients with modest delay and bandwidth su.cient for web browsing.

the system s capacity and scalability are sub ject to DC-net scaling limits with respect to the number of proxies, and overhead per payload bit for cryptographic processing.


It has been argued that, independently of the routing protocol used in the control plane, an Interest cannot loop if it is identi.ed using the name of the content being requested and a nonce (e.g., see [39], Section 2.1).

we show below that this need not be the case even if a nonce were to denote an Interest uniquely.


As computed, the average utility is 78.10 for 25 nodes network, 109.34 for 36-nodes network, 142.84 for 64-nodes network, 203.79 for 100-nodes network, 396.54 for 169-nodes network, respectively.

as the network size increases to 225, the utility increases to only 403.48.


Following the SDN paradigm, the network control plane is totally decoupled from the data plane and most of the intelligence required to manage the network is concentrated in the controller.

our network model intends to go beyond the typical SDN architecture, not only considering the network programmability from the control plane point of view, but also investigating the interactions of internal node functions necessary to enable a programmable data/forwarding plane, for instance one based on hybrid optical technology.


This is true also for multicast receivers, and in [14], both these factors were taken into consideration.

there the objective of the cost sharing was to achieve optimal fairness, which might not be in the best interest of the receivers.


For query and short .ows, all schemes performs similarly under 10% maximum load.


For example, observe that simply changing the objectives without changing the de.nition will result in a different matrix of fair shares T, and consequently a different fairness reference model.

if we want to change the policy, we only need to change Equation (28).


We assume that Random(i,n) generates a random integer between i and n. for i = 1 to n do a[i] = i; // a =[1, 2, ..., n] for i = 1 to n do swap[ a[i], a[ Random(i, n) ]; It is not obvious that this algorithm generates all permutations uniformly.

a security algorithm that is based on such types of generating permutations might be as secure as harder peer algorithms, yet the generation process is still linear.


(WPA/802.1x, SSID GoogleWiFiSecure) 802.11 clients.

aside from the standard prohibitions of SPAM, hacking, and other inappropriate activities, Google does not limit the types of traf.c that can be transmitted over the network.2 it does rate limit individual clients to 1 Mb/sec.


In particular, 94% of the packets are correctly received after one retransmission.

the current approach needs up to 18 retransmissions to achieve the same reliability.


Due to interference on the single channel, only one of them, in this case node 3, can be active.

if all 3 orthogonal channels are used, all the transmissions can take place simultaneously on distinct channels.


Since the boundary cells are slightly smaller than those in the center, the results reported by the simulator could be slightly di.erent from those that would be obtained if all cells were of equal size.

this inaccuracy is not critical, both because it is quite small and because it can only cause our simulator to underestimate the minimum number of nodes in a cell and the network lifetime.


Therefore we have implemented packet-size-dependent delay using linear delay approximation as a function of packet size.

even if our current implementation focuses on payload-dependent delay, we would like to emphasize that the described emulation concept is generic in nature and that an implementation procedure analogous to the one presented below can be used to easily integrate other payload-dependent metrics like, e.g., payload-dependent loss with NetEm.


to new wavelengths, but without changing their route.

it incurs a control overhead (of about 10 seconds), and more importantly, it risks a service disruption in the rerouted lightpaths [32].


Simulations reported in [20] indicate that this protocol outperforms the GAF protocol [17].


With a lower BER pb, the packet loss rate will be reduced according to Equation (7) or Equation (14) when ECC is used.

high transmission power level implies high energy per bit Eb and high energy to transmit a packet.


Furthermore, each DTN router may optionally add its own EID and, in the future, capability indicators (e.g., custody transfer support) to provide further information for a DTN routing protocol.

any such extension comes at the expense of increasing the size of the exchanged packets so that the MTU size limit may be reached earlier and error probability may grow; such trade-offs require further investigation.


When virtual memory is lightly loaded, the marking step can be done quickly.

the sweep step must check and restore all pages.


As we will later see, directed edges in a TDG are very useful in identifying various node behaviors and also in establishing their causal relationship.

we could choose to consider undirected edges, which will enable us to use the more extensively studied graph metrics for undirected graphs, as discussed in later sections.


Therefore, it it is highly attractive to implement contentbased routing directly on the network layer.

since changes to existing standard network protocols and hardware seemed to be unrealistic (as the slow support of the highly anticipated IPv6 standard shows), current research refrains from network layer implementations, and instead tries to improve application layer approaches along several dimensions: (1) inferring the underlay topology from the overlay topology [33, 10, 14, 5], (2) speci.c hardware allowing for e.cient matching of advertisement and subscriptions on network brokers [28], and (3) reducing the expressiveness of content-routing to topic-based publish/subscribe [11].


transmission mode, such as mobile wireless cellular communications.

when system is in continuous data transmission mode, the error propagation of the decisiondirected estimator will cause serious performance degradation.


Decoding times increase as more levels are used since the total number of blocks at lower levels of the hierarchy is signi.cantly higher.

even for multiple levels of hierarchies, the total decoding time is only few seconds, thus, providing an almost negligible decoding overhead.


They assume that when no infrastructureis present, vehicles can only communicate safety data using one of the present ad-hoc protocols.

and in a certain regions, it is important to position a mechanism that can maintain the bothsafety and non-safety data communications when infrastructure is not present (Multi-hop communication).


for higher a, the maximum spanning tree is more slowly approaching the maximumnumberofnodes.


same number of users, at the windy state, the users will experience average packet delay of over 1.5 seconds (s=0.7), which means that the quality of service has been degraded over 50%.

to ensure that the average packet delay is less than 1 second, less than 42 users can be supported under windy conditions (s=0.7), which is much less than in the calm state.


This is the underlying framework of the G-SCA.

our goal is to get a strongly connected subgraph containing a DAS where the number of additional nodes is as small as possible.


A peer may possibly have many queries passing to when its cost of charging for forwarding a message is too low and less queries passing to when its cost is too high.

the deployment of monetary incentive alone cannot prevent the misbehaving peer who may drop the queries from time to time.


We would expect the application to have a higher receiving data rate and a very small transmitting data rate since the primary function of the application is to stream audio from a remote server.

we discovered that RXrate and TXrate are identical.


Additionally, to enable prompt removal of stale information, the location resolver old old new rh informs s that (mach,s ) is obsoleted by (mach,s ).

hh h host locations cached at other access switches must be kept up-to-date as hosts move.


An energy analysis for scheduled access mode has been introduced in [7].

uWB PHY is not considered and ideal channel conditions have been assumed in [6] and [7].


INTRODUCTION AND BACKGROUND Accurate and timely performance data are of vital importance for network administration.

modern networks are so large and transmit such enormous quantities of data that a single backbone link could .ll a terabyte drive in about 3 minutes.


Here, the update messages are voted upon before being sent to the adjacent router.

this is simply comparing opaque strings (the attributes) and does not involve understanding the values in the strings.


In[6], wehaveintroduced the concept of attack detection which we brie.y describe here to provide a full picture of a security design.

in this work we focus on the attack cancelation phase and the corresponding jammingactivity.


TCP Cubic is the default TCP congestion control scheme at boot time.

tCP Cubic can be easily changed at runtime by setting the /proc/sys/net/ipv4/tcp_congestion_control .le to the appropriate TCP version.


The inherent retry mechanism of SMTP added an extra level of robustness to the delivery system.

the routing algorithm of [9] was not tested extensively, as we had a single up-down route, with no BoB-to-BoB transfers.


from the table we observe that the RR measure is only a consistent RNP estimator for the higher quality link (RR > 90%), and the consistency decreases rapidly after that.


Lack of programmability restricts possibilities for modi.cations, extensions and experimentation of MAC protocols.

purely software based modular implementations of PHY-and MAC layers on GPP based platforms, such as the GNU radio [11] on USRP, provide .exibility but often fail to satisfy hard real-time requirements and handle wide signal bandwidths.


[16], 79% of paths we observedhadIPv6performance within10% ofIPv4(orIPv6 had better performance) if the forward AS-level path was the same in both protocols, while only 63% of paths had similar performance if the forward AS-level path was di.erent.

our measurements(and theirs) aredominated by the path RTT because the transfers are typically small (although we only analyze measurements of transfers over 10K bytes).


These methods require no modi.cation or instrumenting of individual end-hosts and hence can be deployed quite easily.

as we show in this paper, they require manual steps and can have high false negatives and positives.


On the contrary, when D is smaller than 0, the actual throughput ratio is larger than the target ratio, and it is necessary to reduce the throughput di.erence.

it may be dif.cult that throughput ratio exactly becomes a target ratio in real systems, and in general, the operation that expands the di.erence may lead to excessive di.erence.


As a part of a scenario description, the expected deployment size of a network, application data rate, and a characterization of its behavior (e.g., bursty or constant application traf.c rate) can also be speci.ed.

the results presented in Section 4 focus only on the Packet Reception Ratio (PRR) and power consumption since we consider these attributes to be highly important for WSNs.


introduced a Multi-Radio Diversity Combiner (MRDC) to collect the signals received by multiple APs and then jointly decode the frame with a frame combining technique, which is capable of alleviating the frame loss due to transmission errors.

the focus of [3] was developing an ef.cient frame combining technique in physical layer.


The upload policy, the underlying graph structure and the initial starting distribution of the data blocks all prove more important, and we will consider varying them in a number of ways.

we will focus on oblivious upload policies that do not require a centralized component to coordinate actions.


The system capacity could only increase linearly as the number of servers increases.

if the number of clients varies in a wide range, system capacity is wasted when the client number is small, and insu.cient when the client number is large.


With retransmission, the per-hop loss rate was further improved to be less than 1 %.

retransmission led to increase of theper-hop delay (Fig.


Our simulation tool permits the IEEE 802.11 protocol emulation in a single cell environment and in a cellular network.

we have observed that the wellknown NS-2 Simulator presents some flaws in a cellular scenario.


Moreover, the true track initiations are only decreased by 7% according to the generic method.

utilizing 4/4 track initiation method wipes out all bene.ts of the elliptic scheme.


Using different spectrum bands in each hetnet layer completely eliminates the interference interactions.

such orthogonal carrier deployments require additional licensed spectrum bands suggesting need for more spectrum for true O(N) capacity scaling and also, corresponding support of these bands in the client devices.


In a typical classi.er rule, the three .elds of source and destination IP addresses and protocol type are speci.ed as pre.xes where all the *s are at the end of the ternary string, so the .elds can be directly stored in a TCAM.

the other two .elds of source and destination port numbers are speci.ed in ranges (i.e., integer intervals), which need to be mapped to one or more pre.xes before being stored in a TCAM.


The error tends to increase when the synchronization messages are sent too quickly (faster than 100ms) except for the one-hop network (Topology 2).

the error is always within the tolerable limit for CSOnet.


For a singleplane routere.ector design, the resulting number of peering sessions is 6,450 and each RR has to maintain 20,000 routes.

if the ISP switches to a multi-plane solution withtenplanes, the total number ofpeering sessionsgoesdown to4,290 while the number of routes in eachRRis reducedto2,000.


The routing load is larger when increasing the number of vehicles (road tra.c density).

dE-OLSR seems more robust than OLSR, since DE-OLSR generates just 30% more load in H whereas the NRL of OLSR increases a 211%.


A longer path or relatively worse path might produce better throughput for low priority packets.

distributing the high priority packets in di.erent paths might also balances the load in the network.


In Aruba Network s Aruba 5000 and Aruba 50 systems [34], the proprietary APs transmit link-layer information feedback to the WLAN switch.

it still falls into the category of intelligent AP systems.


Similarly, accurately modeling the cost of a secure BGP protocol is also dif.cult; for example, soBGP requires exposing all neighboring information, including peering information, to other adopting ASes.

peering information can be highly valued by some ASes [13], thus the cost of adopting soBGP for these ASes may be higher than others.


Energy-Efficient Opportunistic Topology Control in Wireless Sensor Networks Jian Ma, Qian Zhang, Chen Qian, and Lionel M. Ni Department of Computer Science and Engineering Hong Kong University of Science and Technology Clear Water Bay, Kowloon, Hong Kong {majian, qianzh, cqian, ni}@cse.ust.hk  Abstract Topology control has been proposed as a promising technique to achieve energy-efficiency in wireless sensor networks (WSNs).

existing topology control algorithms assume that wireless links are static, either connected or disconnected.


Since the DST processes these packets in application layer, we could not acquire enough accuracy of time gap of two acknowledgments.

packet Train exploits more than two packets.


Broadband users on fibre contracts do seem to have sufficient spare capacity that PAWS did not intrude on their own experience (certainly none of our measurements indicated such problems, nor did our sharers report any).

given the poor quality of service that we observed ADSL users can experience, there may be a case for LBE protocols to be applied there.


Indeed, although it would be possible to implement such individual structure within NSGA-II/III, these algorithms do not provide natively this kind of .exible encoding, that is crucial to this problem.

µGP o.ers o.-the-shelf various encoding schemes, thus requiring a much smaller coding e.ort on the algorithm implementation, and allowing users to focus on applications rather than algorithmic details.


But trees are not good for fault tolerance.

as mentioned earlier, so long as we do not have multi-path routing, we only need a tree active at any point of time.


PROPOSED TECHNIQUE 4.1 Proposed Algorithm TDAR relies on fully adaptive routing algorithm to better utilize limited bandwidth of TSVs.

under certain traffic patterns, fully adaptive routing can cause inefficiency to the network performance.


Hence, our notion of security does allow a server to accept the same message twice, but only if it also has been sent twice.

the server has no way of knowing whether a message that has been received twice was also sent twice.


Thus, with a threshold of 1.0 our algorithm identi.ed 8 different SRLGs as being involved.

as the threshold was reduced to 0.9, we were able to isolate the fault to only 2 different SRLGs.


INTRODUCTION IEEE 802.11-based multi-hop networks are a popular technology for wireless communication.

since commodity IEEE 802.11 transceivers are half-duplex single-channel devices, performance suffers significant degradation in these environments due to medium sharing and interference along the multi-hop paths [1].


Here, the assumption is made that , data packets associated with HPD indicates a higher priority data demanding high reliable service.

data packets tagged with LPD and MPD can be delivered to base station tolerating certain delay and percentage of loss.


As mentioned above, when m is T(N) and q is T(1), both active and inactive constraint regions are possible.

it turns out that in both cases the () N3/2 scaling shows the same order (T ).


When the BS capacity doubles, energy-saving gain increases by about 10%.

as we vary BS capacity, the maximum energy-saving gain (when traf.c is lightest) is almost invariant.


Their target applications are group protocols and XML protocols.

this work is limited to secrecy, and the class of protocols that they handle is limited to protocols that treat all elements of lists uniformly.


Considering this last observation (which holds for relay-set sizes from 5 to 100), there seems to belittlejusti.cation for using the Jthreshold test.

since this technique does reduce the number of transmissions, it reduces the overhead and saves power.


Under this assumption, a 2x2 MIMO system is able to use the maximum power of only a single node at a given time, since only one of two communicating nodes can transmit at a given time.

with full duplexing, the system can use the maximum power of both communicating nodes at the same time, thus allowing the use of more total power in system.


They have proposed several modifications to make the MIP more practical for multihomed MSs.

none of the abovementioned reference can completely solve all the problems related to multihomed MSs, and it will take a long time to standardize the MIP improvements.


In this condition, our proposed methods can achieve high coverage such as 86% for the MIDDLE poisoning and 90% for the MIDDLE+BOTTOM poisoning, but both methods still can not achieve the same poisoning effect as the conventional method.

increasing the lifetime of .le keys gives more duration for indirect index poisoning effect to take place in the network and the MIDDLE+BOTTOM poisoning can achieve the same coverage with the conventional method (96%).


Further, past work on RF-based gesture recognition requires modi.ed hardware [27, 10, 9].

rF-IDraw is a software patch that can be added to today s standard RFID readers, and does not require any hardware modi.cation.


This is because lowering the rate can increase the transmission range so that the interfering nodes are more likely to sense/capture its packets and consequently back o.. Also, packets sent at lower rate are more robust to interference or noise.

previous work has also shown that lowering the sending rate results in signi.cantly low network utilization [31] and, in certain cases, can even worsen the unfairness problem [34].


We also ignore .ow age as a criterion for termination.

if the unsampled .ows are measured .ows, their ages do not exceed the allowed maximum.


3) Data Aggregating: If a sensor node has more than one sensor, sensed data obtained from different sensors must be placed in packets.

data sampling rates may vary by sensor, and in some cases, post-processing must be performed on raw sensed data prior to data packing.


Another popular option is to train students about attack techniques, arguing that thinking like a hacker enables one to protect against them [1].

others argue that it is better not to train additional hackers but to emphasize security techniques Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page.


A is not required to report positive feedback for B.

if A is dissatis.ed with the transaction operation, it will explicitly report a negative feedback for B.


In this case, our hybrid network can use fewer mobiles than all mobile networks when k =1.

the improvement ratio reduces as k increasesasin Fig.


Also the first prototypes of QoS adaptation components are demonstrating the viability of the approach, at least if considered as separated basic mechanisms.

since the characteristics of the QoS adaptation compo- nents are tightly connected to the nature of the interested service, we expect to obtain significant feedback from the performance results we are collecting in the implementation of a multimedia distribution service capable of adapting to groups of heterogene- ous QoS-requestlng PDA receivers.


The most intuitive solution for an implementation would be, that the server sends a noti.cation message to the client as soon as the state change occurs.

when client and server communicate using the request/reply protocol just described, this seems impossible.


Inthe R subphase, RO rejects no calls and is optimal.

the A subphase begins when algorithm R rejects a call C. RO accepts the same calls as algorithm A except possibly for C. BRO(st) = 1 since RO uses lazy rejection.


Or perhaps when it appears that the only hosts still contacting the old address are faulty?

the original expectations for D-root s changeover were that (1) the vast majority of traf.c would migrate over to the new address relatively quickly, (2) the only remaining traf.c would be due to faulty servers or botnets, and thus (3) a few months of running the old address would suf.ce.1 the changeover has not been as rapid in practice: 63% of sources do not switch over after four months (by May 2, 2013), and they generate 4,721 queries per second on average.


How much trust improvement can be achieved using multiple paths is a question they have tried to answer by proposing di.erent kinds of trust metrics.

none of these approaches consider the revocation problem.


(Xj <x,.jE.,j= d)) dx (4) 2 A non-constant distance between nodes can be also chosen.

a constant distant t allows a fair comparison of the di.erent regions (connected, transitional, disconnected).


In a design of a cellular network, such high peak traffic becomes a target, i.e., it is required to provision for peak traffic levels, which makes installed femto/pico cells or wireless LAN APs underutilized at off-peak times.

there are some infrastructure-less communication technologies, e.g., adhoc network [5], delay tolerant network (DTN), etc., that have been considered as a promising means for communication in a challenged situation such as severe natural disaster.


If a peer receives a query that requests resources  belonging to its super-classes, it forwards the query to higher clusters.

if it receives a query that requests resources belonging to its subclasses, it forwards the query to lower clusters.


It can be seen that the mean RTT/2 value lies in both cases between the mean OWD measured for the TCP data and reverse paths, something reasonable given the packet size of the ICMP test traffic.

neither the mean nor the distribution summary of RTT/2 can adequately estimate the unidirectional contributors of the round-trip time.


Another approach is to price scarce resources.

while congestion pricing has been suggested as a way to combat DoS attacks, it has not been shown quantitatively how much damage a malicious player could cause to the utility of benign participants.


These tools provide libraries for building scienti.c computing applications and running them on the cluster.

the capabilities of these tools doesn t extend very well for streaming applications.


Virtual buffers and link selective rate control avoid the waste of bandwidth problem inherent to TCC.

lSCC also has an inherent inef.ciencywhich leads to bandwidth reductions.


We observe that about 40% (50%) of LDNS (ADNS) NACs have no failures correlated in this manner.

on average 11.5% (12.2%) of failures were correlated in a given NAC.


The high population density of the zebras allows for multi-hop radio communication in a relatively limited area.

cranes travel in isolated family groups of two or three, which makes it impractical to solely rely on multi-hop communications.


For example, if we use G.726 at rate 32 kbps, with a header size of 74 bytes and a PI of 10 ms, the required bandwidth is 32 kbps+74 bytes/10 ms=91.2 kbps.

with a PI of 20 ms, the required bandwidth reduces to 32 kbps+74 bytes/20 ms=61.6 kbps.


LEARNINGOF COORDINATIONATAP The good performance of CCMAC depends on the ability of the AP to perform proper coordination.

it is a big challenge for the AP to learn this, because the network is stochastic and the AP does not have the full knowledge of the network.


10(b) and 10(c) plot the packet loss rate of the competing technologies: the DSSS phone and ZigBee.

the .gure shows that if 802.11n transmits concurrently, without TIMO, these technologies can suffer signi.cantpacketloss.if802.11n employs TIMO,thenitsinterferenceincreasesloss ratesbylessthan0.5%, whichis negligible.Thus,TIMO canhelpdiverse technologies coexist in the same frequency band while placing the burden of interferenceprevention onhigh-endMIMO nodesinstead oflow-end single antenna systems.


In both cases, to keep the queue length close to the target value, the AWM algorithm tries to increase the TCP source sending rate by indicatingalways increasing values of the suggested window.

the TCP sources are not allowed to increase their sending rate because they are driven by either the forward and actual bottleneck node, or by the user tra.c; so AWM indications do not take e.ect.


In [25], the authors proposed to extend this approach by encapsulating I/O processing into a VM.

all the previous studies focused on the processing of I/O protocols instead of providing virtualization of I/O devices.


The problem is further formulated as an optimization problem which minimizes the variance of sensors in di.erent regions in [17].

both [8] and [17] do not provide performance bounds for fraction of area covered or maximum moving distance.


Transceivers for copper cables are Si-based semiconductors, and are ideal for short-reach interconnects.

the de.nition of short has been trending downward over time.


Given thatTCPprocessing overheads are typically dominated by the checksum computation and segmentation, and that these tasks are increasinglydelegatedtohardwarein modernNICs, webelieve that this assumption is quite reasonable.

vFlood still has to carefully manage the .nite amount of bu.er space for .ooded data among multiple connections.


We have already collected similar results with the PCA method described in [5].

more progress needs to be made on PCA understanding before we can have enough con.dence in these results [9].


The bene.t would be a less complex driver freed from link diagnosis.

the challenges for rapid noti.cations in this case are the high frequent polling for the actual measurements from the driver and the speci.cation of a powerful API to accommodate for complex queries.


This addresses directly drawback (i) and reduces the probability of drawback (ii).

incorrectly implemented, PFC can still generate switch memory-to-memory (M2M) circular dependency and routing deadlocks.


In this step, if all cells labeled smaller or equal to i are used, no additional work needs to be done.

it is possible that due to the participation of buffer cell i of each wavelength, some of the buffer cells labeled i- 1or smaller that were used in step i- 1now cannot be used.


The results obtained are closely related to our own.

the question of a distributed implementation remains.


We experimented by varying a from 0 to 1 and observed that RCE was not signi.cantly sensitive to a (in spite of a = 0, MCD exhibited a low RCE indicating that once the sensors reached their target angles, choosing the direction that minimized the distance between the hull and the actual centroids resulted in the sensors converging onto the contour).

latency showed 5Applied Science Associates Inc., http://www.appsci.com/ 6GRAM++: Full runtime GIS supporting Vector And Raster map data creation, query, analysis and layout application, http://www.csre.iitb.ac.in/gram++/ some variation with a and at a =0.5, both the SA and the MCD algorithm displayed a low latency value.


Our experimental setup used active scanning to probe for nearby access points.

aPs can sometimes be con.gured to not respond to broadcast probe packets.


2.1 The Push/Pull Envelope When sensor data are needed at a constant rate, push requires less downlink traffic (cloud to edge, edge to sensor), since the application issues one subscription request only, then acquires the stream of values from the sensor.

pull incurs a roundtrip penalty for each data query (e.g., involving steps such as request, transmit, receive, and acknowledge).


To properly select the number of clusters, a number of studies have focused on derivation of energy models to estimate the energy consumed in the network with respect to the number of clusters.

their accuracy is not satisfactory due to their .awed assumptions.


If the .rst approach is used, management data and sensing data can be aggregated by the sensing application in order to reduce the additional communication costs for the management framework.

this implies a severe disadvantage: Every time a new application is developed, the management functionality has to be reimplemented or at least reintegrated.


Whenever T-RAT was unable to determine the correct rate limiting behavior, its estimate of the RTT was incorrect.

correct RTT estimation is not always necessary.


Anonymization, while inherently an information reducing procedure, must be measured in terms of the amount of information that is lost in the .le.

by anonymizing we can introduce new false patterns into the data.


In our context, precision can be de.ned as the ratio of the number of Nugache peers in the returned list of hosts to the length of the returned list.

recall can be de.ned as the ratio of the number of Nugache peers in the returned list to the number of all Nugache peers in the network except the seed bot (m - 1).


In previous research, many algorithms had been proposed to reduce the consumption of power, but most of them only considered multiple connections in a Mobile Subscriber Station (MSS); in fact, it does not fit in with the situation of real world.

others proposed algorithms considering the situation of multiple MSSs with multiple connections; nevertheless, it is difficult to increase the amount of MSSs.


As mentioned previously, FRuG does not use seeds as ClassBench does to generate classification tables.

considering that EffiCuts produces very different results when the size of the rules and the overlap between them vary, we implemented two scenarios in FRuG: a small scenario with little overlap and mostly small rules (best case) and a large scenario with a lot of overlap and a wide variety of rule sizes, including wildcards (worst case).


In proactive routing protocols, all the nodes are known beforehand, and similarly, if using proactive service publishing, all the services are known throughout the network even before there is a need to invoke them.

in on-demand routing protocols, the route to a node is discovered only when needed, and similarly, if using on-demand service discovery, the needed services are discovered only when it is requested.


4.4 Synchronized Channel Sensing on a DualRadio Platform The experiments with the radio array platform have shown that simultaneous occupation of adjacent IEEE 802.15.4 channels is a reliable indication for a Wi-Fi transmitter detection.

using an 8-radio or a 4-radio platform for detecting Wi-Fi signals on the host platform involves a high communication/coordination overhead for the master microcontroller.


We show that, for the .rst time, measurements taken by commodity NICs can accurately predict whether links will work over a wide range of rates, transmit power, spatial streams, and antennas settings that have not previously been tested.

predictions based on RSSI often confuse from two to .ve rates as the potential best rate to use.


The Chord protocol is also similar to Pastry, the location algorithm used in PAST [8].

pastry is a pre.x-based routing protocol, and differs in other details from Chord.


This, in general, 12 demands a unicast exchange of messages between Tx and Tx , 12so that the latter reveals its current transmission power.

by using the fact that when FM fails to find a feasible solution, all transmitters below their targets transmit at Pmax, this exchange is not necessary at least for the first round of BFM.


How the multiplexing is controlled by the sensors in a distributed fashion is an important problem.

we defer discussion about the problem till Section 4, and assume a simple ALOHA like scheme for the rest of the section.


This approach clearly approximates the true redundancy pro.le as described in Section 3.1.

our trace-based evaluation (Section 6) shows that the inaccuracies in our approach do not sig ni.cantly affect the quality of the routes we compute.


Like GTFT, Catch relies on the mechanics of Tit-for-Tat by assuming cooperation and punishing free-riders.

while GTFT requires knowledge about the utilities of all the nodes in the network, Catch relies only on information collected in the one-hop neighborhood of individual nodes.


Sooner or later, by reverse engineering the obfuscated code, dedicated attackers can eventually retrieve the secrets from a compromised node.

it is also widely believed that compromising one or a few node does not always achieve an e.ective attack.


3.3.2 Packet Delay Ideally, we want to measure one-way delays from the probe host to the Beacon host to study the impact of routing changes on packet delays.

such measurements are subject to limitations due to the clock skews on PlanetLab sites relative to the Beacon host.


Multiple solutions have been proposed by industry and academia with this vision.

they are either plagued by scalability issues or unsuitable for applications requiring stringent QoS and backward compatibility.


The paths between pairs of nodes are encoded as the chromosomes of a genetic algorithm and constraints such as maximum diameter and nodal degree are given.

this work solves the problem for only 20 demands.


Such commercial deployments re.ect the industry acceptance for GPPs used in BS design.

vanu s solution is for 2G and FDD systems , where the system requirements are far more relaxed, no matter for throughput or timing control.


It should also be noted that Simultaneous Multithreading (HyperThreading) was turned o. for the duration of the tests.

exhaustive tests with HyperThreading on this architecture are underway.


Thisvalueisrecommended by Internet RFCs [6], architectural guidelines, and network operators.

several recent papers propose con siderably reducing thebu.ersinbackbone routers[4,9,23].


Selecting the channel with the longest expected idle time is intuitively the optimal way from a single user perspective.

it may not be e.cient in a multi-user network.


Of course, router failures are typically easy to identify through spatial correlation, as all of the links impacted have a common end point (the failed router).

optical layer impairments can impact seemingly logically independent links at the IP layer if these links are all routed through a common optical component, making them much more dif.cult to identify.


CAPTCHAS [36] and .ght .re with .re [37] are two existing technologies that address this issue.

cAPTCHAS requires modi.cations to the existing server while Wal.sh et al.


This is the conventional mapping considered in C-RAN currently.

in DAS, a single frame is transmitted by multiple RRHs, which in turn can be accomplished using a single BBU, thereby requiring a one-to-many mapping.


The results show that the kNN algorithm performs better than the p-kNN algorithm when the target is positioned in the intermediate positions.

when the target is in one of the .ngerprint positions, the p-kNN algorithm has a better performance.


The IEEE 802.16 standard defines the specification for Metropolitan Area Networks.

it does not define the scheduling schemes for different service classes.


We note thatby extending the precomputation algorithmtoprecomputefortheedgeswitcheswe can reduce the recovery for all links and device to a constant time of under0.2 second(Cachelook-uptime).

doingthis will require allocating more memoryfor the cache.


When horizontal misalignment occurs, the grid deployment can always guarantee coverage by scaling back the designed distances between sensors.

when vertical misalignment takes place, the grid deployment cannot guarantee complete coverage if two neighboring rows are separated by more than 2rs , no matter how small the designed distance is between sensors.


Their solution also relies on an interrupt handler based approach.

they only consider the RDMA write based semantics and not RDMA read.


It will thus not be able to choose a path via an area i .0 for a destination D if D is not in this area.

b R1 = could be on the shortest path from a router X in area i to the border router B R2 that X selected for destination D. When a packet with destination D, entering the network in X will reach B R1, it will be forwarded into the backbone, instead of being forwarded to B R2 and only then be forwarded into the backbone.


On the other hand, the addressing of a standard DRAM today involves a complicated procedure of time-multiplexing of address and data in order to save pins.

since TSV technology promises to provide many more pins, we are not necessarily restricted by pin out, since we would be able to provide both ROW and COLUMN addresses simultaneously.


There is an interesting postive feedback in 802.11 MAC: When the network load is heavy, the collision probability gets high, and thus more losses incur more retransmission.

this behavior implies that nodes are always injecting more traffic into the network when network condition is bad and making the condition worse.


The hidden node problem can be solved by a RTS-CTS handshake mechanism proposed by MACA [10] (RTS stands for Request to Send and CTS for Clear to Send).

in a heterogeneous wireless ad hoc network, a hidden node should be de.ned as a node out of the range of the sender and whose range covers the receiver.


WiFiPro.ler shares this basic idea of leveraging passive observations made at end hosts.

the wireless setting is unique in the opportunity it provides even disconnected clients to share information with their peers.


It is also noticeable that there are much more lowvolume users in the DSL plot.

the boundary of the two clusters is not very clear.


proprietary research is not open to public (and public scrutiny) and is often driven by vested interests.


Similarly, CENTAUR[21] uses a central controller to reduce throughput loss due to hidden terminal and exposed terminal problems.

their solution is also applicable only to downlink tra.c.


Link Layer Assisted Mobility Support Using SIP for Real-time Multimedia Communications Wooseong Kim , Myungchul Kim , Kyounghee Lee , Chansu Yu and Ben Lee School of Engineering Department of Electrical and School of Electrical Engineering and Information and Communications Computer Engineering Computer Science University, Daejeon, Korea Cleveland State University Oregon State University {wskim, mckim, Cleveland, OH, USA Corvallis, OR, USA leekhe}@icu.ac.kr c.yu91@csuohio.edu benl@eecs.oregonstate.edu Abstract Session Initiation Protocol (SIP) was standardized for real-time applications and extended to support terminal mobility by Internet Expert Task Force (IETF).

sIP terminal mobility suffers from the considerable handoff latency which is unsuitable for the real-time communications.


During the measurement period, we also ensure that the network was free of cross traf.c, packet loss, and retransmissions.

although the web server could bias the RTT, the bias, if Figures 3(d), 3(g), and 3(j) show that the delay overheads incurred by the socket-based methods are considerably small.


The corresponding probability distribution then reads s 0 if |c| = |s|, layered pcs (X)= Xs(1) if |c|= |s|. ''

s:|s'|=|c|X s in .at systems, users are assumed to sample uniformly from the total population of users when selecting a target user.


= 0.1 Figure 6: Effects of Multiple Trees (Scenario A, No Rearrangements) Also we see that setting smaller a can occasionally improve the performance further.


The accounting gap caused by hybrid networks is not as large as that with insuf.cient coverage.

it is more often observed than the former case, and it may last for longer time.


On the one hand, multiple receivers may overhear a single transmission on the same channel at no additional cost above a point-to-point transmission; this property has been exploited in many opportunistic applications (e.g., [2]).

the shared nature of the medium e.ectively forces wireless nodes to leverage frequency diversity and channelization for e.ciency.


One of the drawbacks of backing o. is that the SU may miss some part of the white spaces during backo.. An alternative approach to backing o. is to continuously sense the channel so as not to miss any white space.

this approach is highly energy in-e.cient (specially for battery operated small mobile SUs, and cognitive sensor networks) because the SU devices need to sense the channel even if they have no frame to transmit.


[13] use location correlation to .nd shared-risk link groups of network components.

we determine the shared-risk link group based on whether IP links share the underlying layer-2 infrastructure.


Once the sources are in Congestion Avoidance, RED is able to keep BO below maxth, avoiding additional overflows, and achieving better performance than the Drop Tail scheme considered in Section 2.

bO reaches higher values with RED than with SBD, even with RED having a lower minth value.


In fact, since receivers share parts of the multicast routing tree, this assumption does not hold in real networks.

if all classes have similar trees no protocol class is privileged relative to another one by this assumption.


Early in the process, the propagation rate along both the edge and diagonal are identical.

the propagation rate along the diagonal drops to nearly 20% of the original rate once it reaches node (5, 5).


When the all-at-once strategy is used, CoAST reduces buffering time by 66%.

it also increases the energy consumption signi.cantly if the entire video is downloaded.


It is not strictly necessary that traffic information is encrypted.

we propose the encryption of such communications in order to avoid passive nodes, which collect traffic information exchanged among other users but do not cooperate in the network.


This formally justi.es the design of S-BGP as a means to protect against some of the major threats.

we also show that S-BGP does not guarantee route validity by presenting explicit attacks under our de.nition.


DISCUSSION AND OPEN QUESTIONS Many signs of excitables point to PowerDNS: it is most popular in Europe (where the majority of excitables come from), we have identi.ed that some versions include both of D-root s IP addresses in its list of root name servers, and its root selection algorithm can send all queries to a single name server.

our runs of fpdns have turned up only a single PowerDNS resolver running an old version of the software.


If a network synchronization protocol is present then the funneling-MAC can use that and further minimize its active beacon signaling.

in our implementation of the funneling-MAC we do not assume this and integrate a light-weight clock synchronization scheme embedded in the beacon messaging.


Protocol translation is useful when interoperability between different protocols is required.

there is unlikely to be a direct mapping between the functionality provided and required in heterogeneous discovery applications e.g.


A node at the edge of a WLAN could provide coverage to areas that are outside the range of the AP.

in this paper, we focus only on the rate anomaly problem.


It may be possible that mid-scale disaggregation (resource disaggregation at the rack-or pod-level) would provide enough ef.ciency and .exibility.

we speculate that having a .at, uni.ed interconnect across a datacenter can be much simpler than the two levels of network structure, in terms of the design and scheduling complexity.


For the any- 2-any and leaf-2-1eaf models, shown in Figure 8(a), the maximum edge congestion scales almost identically to that for shortest path routing (compared with Figure 5(a) and 6(a)).

somewhat surprisingly, for the clout model, congestion under policy based routing scales only as n 3 compared to over n 5 for shortest-path routing.


It reaches a consensus that many protocols and algorithms developed for traditional WSN no longer suit to the unique features and application requirements of WBAN.

wBAN presents unique advantages, such as reliable and accurate physiological measures, to advance modern technologies and to benefit the global society [4].


The NDN implementation treats CCN as an overlay using TCP/UDP between CCN overlay nodes.

we believe a tightly integrated approach as proposed here provides the best of both worlds, with COPSS routers at the edge and at selected points, and the core routers in the network only performing IP forwarding.


They directly a.ect the signaling overhead and quality of calls in the system.

they are di.cult to analyze due to the irregularly shaped network topologies introduced by multiple tiers of cells.


Ideally, if good nodes and malicious nodes present totally different statistical behavior and the statistical metrics distributions for good nodes and malicious nodes have no overlap, then we can set a threshold to perfectly distinguish the good nodes from the malicious nodes.

in practice, the metric distributions always have an overlapping area.


In the case of those users, 20% of them accounts for only 60% of all videos posted to each of the groups they belong to.

80% of all uploaded videos to those groups are due to almost 60% of their members.


Successive handover failures could eventually lead to a Radio Link Failure.

if the handover request is granted, the handover execution phase is initiated followed by the handover completion phase.


Thus, the root controller is the only controller able to run Appreroute.

appdetect is local; therefore, all controllers can run it.


The constraints in the above system are always satisfied for a central channel allocation scheme.

our goal is to achieve fully decentralized channel allocation.


Then, both Aand Cwould switch to the route via AS 3, which may lead to a change in the properties of the endto-end paths for traf.c entering AS 1 at routerC.

the link failure does not cause a change in the BGP route at Dand, as such, the change is not visible to the measurement system.


The result of Mode 1 extends lifetime 2.87 times than that of Mode 2 and at least 3.65 times than the other two when the value of K all equal to 8, which means in the case of K=8, Mode 1 prolongs the lifetime of network by unequal widths adaptation of rings.

it performs worse than Mode 2 when K in Mode 2 is 20 and 25.


This scenario is very similar to those scenarios used in the wired networks for testing RED scheme.


Although we do not have the statistics, we do believe many users prefer using the apps to access the content providers, in particular for those popular ones (e.g., top 100).

lessons and recommendations derived from this study are generally applicable to any mobile web page.


For example, we expect thatsimilar qualitative .ndings about the impact of infections and the presence of heavy hitters hold in networks of di.erent type.

we expect that the volume of infections will be lower in more tightly managed environments.


This is the same customer/provider relationship as before.

the zero-dollar peering relationship does not happen between all pairs of transit ISPs.


Particularly, under the benchmark policy, the throughout is saturated if the load is larger than 0.52; the delay increases sharply when the load increases from 0.5 to 0.7 and gradually increases if load is greater than 0.7.

the average end-to-end delay under policy 2 increases much slower.


Actually, both protocols still operate with topologically organised addresses (either inside a realm or inside the existing global Internet).

our proposal merely uses IP addresses to maintain a backward compatibility with existing applications that mostly operate in an IP-by-default manner.


Our dynamic analysis approach is resilient to obfuscation techniques designed to thwart static analysis such as binary packing and inlining unnecessary instructions.

a premise of our approach is that we can observe a sample s processing of the received data in our analysis environment (based on a system emulator).


Therefore, a station could become active when it has to start a communication and then the need of paging a dormant host does not exist.

this scenario is dramatically changing due to the massive introduction of portable devices as WiFi enabled PDAs or phones and the interest in VoIP over WLAN.


(27) is obtained from the fact that if the new connection is accepted and allocated r +n units of bandwidth, the payoff for the base station becomes the total utility of the ongoing connections after some portion of bandwidth have been taken away (which results in decrease in the total utility for the ongoing connections) plus the utility of the new connection.

if the new connection chooses to deny the offered service, the payoff for the base station is identical to that when the base station rejects the new connection.


The physical layer design for future multichannel multihop wireless networks is not clear.

in the widely-deployed IEEE 802.11b standard, three non-overlapping channels can be used simultaneously.


For window sizes of 1 second we obtain recall and precision of 94 and 92% respectively which compares well with recall and precision of 85 interarrival time alone (92 and 65%) and large packet lengths (recall 72% and precision 80%).

there is considerable 80 Precision is between 90 and 95% for the same window sizes but declines to 85% for a 10 second window.


# of messages vs. rank of phone numbers (log-log scale) 1e+07SMS Sent SMS Received RINGTONES Received 1e+06 100000 # of messages 10000 1000 100 10 1 1 10 100 1000 10000 100000 1e+06 1e+07 1e+08 Rank of phone numbers Figure 2: Messages per phone number versus the of the curves in the .gure.

quite a few phone numbers send (and receive) thousands of messages within the 22 days, which cannot be explained by normal human activity.


This approach works well for a dense network.

it may generate faulty positions in sparse networks where global incorrect .ip con.gurations cannot be escaped.


The difference may come from limitations and assumptions they used in this work.

the two methods we have proposed require a re-authentication latency lower than the 50 ms limit even at high loads.


Without a testbed with both capabilities, earlier work on the interplay between interdomain and intradomain routing used simulations [20].

a researcher is using PEERING to study man-in-the-middle hijacks, in which an attacker uses BGP to intercept traf.c to inspect before forwarding it to the destination [44].


We believe that addressing this would require the consideration of multiple channels, and channel assignment in parthis, the AA step ends up choosing to use a 60o antenna at one or more nodes.

the side-lobe pattern of these antennas are allel with the four variables that we have considered.


The fairly rich structure of the key and nonce types makes the approach very .exible, and expressive.


In other words, a switch from PTP to PTM resources should occur, when the number of users in a cell exceeds a predefined threshold.

this approach suffers from much inefficiency, mainly due to the difficulty of defining the appropriate threshold.


This strategy enables fast lookup resolution in spite of highly dynamic node membership, which is a signi.cant problem in the Internet context.

with the inherently higher packet loss rate in a MANET, this failover strategy results in lookups being inconsistently forwarded even if node membership does not change.


From 08:00 to 20:00 local time, median / 95th-%ile .ow concurrency is 253,000 / 343 k.ows, while overnight, it falls to 91.4 / 166 k.ows.

night-time transient peak concurrency is comparable to that during the day.


Figure 6(b) shows that in the uplink the power increases with the load.

in the downlink the power initially increases and then decreases.


Due to the unicast property of the RTS/CTS handshake, the sender of the RTS message could ex pect which node will reply the corresponding CTS mes sage.

the RTB/CTB handshake is designed for broadcast.


at one end of the spectrum are denselydeployed networks, where in core areas, nodeshavefull connectivityandhighlink quality.even in such well-provisioned environments, supporting demanding applicationsisdif.cult.Forexample,VoIPcanperform poorlybe causeoftherequirementsforlowpacketloss,delay,andjitter [5].At theotherend,inareas whereinfrastructureisunavailable,onlyDTN basedoptions arefeasibleandthey workonlyfor non-interactive applications [4].


Let the number of these edge-disjoint paths be h. If h is greater than or equal to n + 1, then our approach can be applied directly, and the combinations formed in Ls can be forwarded to the sink.

if h is less than n + 1, then the formed combinations cannot be forwarded as is, and our solution must be modi.ed.


In this approach, tags responde almost immediately to the polling event.

the wake-up circuit requires the reader to be close enough so that the radio power is strong enough to trigger the wake-up event.


These di.erences are not unexpected given the disparity in the RF circuitry, antenna design, manufacturing tolerances, and sampling performed by the driver.

in all cases the BLR exceeds 5% when the RSSI drops below -80 dBm.


rate, since congestion control of TCP provides a graceful scale-down of individual .ows.

signi.cant effort is needed in choosing and tuning an appropriate TCP method to sustain multiple Gbps .ows at thousands of miles.


Link asymmetries are automatically addressed by relying on layer two acknowledgments [26], because links are deemed valid only if transmissions are successful in both directions.

if an existing link becomes unavailable, a route breakage is signaled if the maximum number of (re)transmissions is exceeded.


Box 3030 Irbid, Jordan +962-7201000 fhawad@just.edu.jo ABSTRACT The IEEE 802.15.4 Wireless Personal Area Networking standard, which was designed for low-data-rate and low-energy-demanding wireless networking technologies such as wireless sensor networks, provides a Guaranteed Time Slot (GTS) algorithm that offers the nodes requiring low-latency channel access to reserve contention-free time slots.

the standard limits the number of simultaneously allocated GTSs to seven, which increases the failure rate of accommodating a growing demand for GTS allocation.


The first OFDM frame is fully used, but the second one is a fragmented OFDM frame.

since the 2nd OFDM frame has unused bandwidth, the BS allocates it to MSS C. as the remaining bandwidth is not enough for MSS C, the BS will allocate part of bandwidth in the 3rd OFDM frame to satisfy MSS C s bandwidth need.


In our simulation, we have found no frame loss and no delayed frames when the switch buffer has been limited to 1MB.

limiting the buffer at a larger size such as 2MB leads to a signi.cant number of delayed frames which violates the delay requirement.


If either of these situations occurred, traceroutes along the tested path would likely reveal multiple possible routes.

despite our continuous sampling of the path with traceroute during a BFind test, we did not observe either of these routing problems occurring frequently.


Our performance analysis shows that both the size of the coalescing queue and the duration of the coalescing timeout should adapted to the o.ered tra.c.

we show that a dynamic coalescing approach can be used, which seamlessly adapts to any tra.c conditions, and achieves nearly optimal results in terms of power saving and packet delay.


Predicting the level of such increase is challenging since it should correspond to the expected duration of disruption.

in our initial study here we investigate routing performance assuming that estimation can be either accurate or within a margin of error level.


When the disconnection periods are in the order of hours, the service will satisfy few participants.

we leave the signi.cant task of measuring the exact tolerance of users to delayed delivery for our later work.


As a community, we focus on design principles that deliver such virtues as robustness, scalability and manageability in the face of complexity, component failures, growth, and other challenges.

as the Internet becomes mainstream it inevitably moves from being an engineering curiosity to being a mirror of the societies in which it operates.


We implemented the online portion of the kmedians algorithm from scratch (about 300 lines of C++ code), while we used the C clustering library [5] for the o.ine part.

the library had to be modi.ed to support clustering data with weight (i.e., count of entries clustered to a candidate center at the online stage).


The proposed method to achieve this goal is reported below in Section 3.4.

ranging results of the system above described in Section 2.2 show that, even when direct visibility exists between the MT and the AP, the obtained RTT measurements are noisy and present a noticeable variability.


This way, we can guarantee the workconserving property of the partitioned hash tables, because edges to be queried for an active node ID must be dependent to each other, and stored in different hash tables.

since M is a user-specified parameter, M hash tables may not be sufficient to avoid the dependency among all edges.


Thus, whenever the user translates the device, the relative position vector of both its antennas remains the same.

as the device rotates, the relative position vector of the antennas, also rotates.


It is because OP-I uses RRC Connection Release with redirect, which can be triggered atRRC Non-IDLE state.

oP-II users get stuck in 3G muchlonger because OP-II performs inter-system cell selection, whichoccurs only at RRC IDLE state.


6.3 More on Correctness Consistent con.gurations: The bandwidth overhead for dissemination is low as the con.guration .les are quite small (1-2 KB per device).

differences in the distances between the devices and the NOC could lead RE devices to use inconsistent caching con.gurations.


I Pj (fj )= Pk,j (fk,fj ) (2) Our proposed approach allows the MRs to use more than .k.SjT ,fk.CkT one transceiver for sending and receiving data packets con currently.

each transceiver must be tuned to a di.erent half duplex channel.


Regardless of the treatment of hosts with unknown estimates and the degree cap policy, the Resource Index is always above 1 during 19:00 -21:00.

a degree cap of 6 places more constraints on the resources in the system and could potentially make it more dif.cult to construct a tree with good performance.


As a result, these schemes increase the synchronization delay for scenarios in which only one (or a few) blocks are suf.cient for detecting the spike.

our algorithm adaptively processes more data when the spike is too low for detection, and hence gracefully scales with the SNR of the received GPS signal.


Also, GOR yields the same miss ratio because it selects the forwarder that is closer to the .nal destination.

in a heavy tra.c environment, ORTR outperforms because a forwarder of nodes that successfully receives data is selected through one broadcast.


Through the proportional selection, the probability of selecting a given chromosome is proportional to its .tness.

ordinal selection combines the proportional selection with the random selection.


It is due to the need of extra place to store the sack block information.

it is not the worst performer due to better retransmission and recovery techniques implemented to it.


The primary ob jective of multi-homing is to provide enhanced reliability during the failures of a provider network.

it is also desirable to exploit multi-homing for performance optimization such as load balancing and minimizing network latency.


Existing techniques include Reed-Solomon codes [8], Luby Transform Codes [9], Digital Fountain [4], Turbo Codes [3] and other LDPC codes [10].

all these traditional channel codes require accumulating a large number of initial codes before decoding, which is not desirable when resource is lim environment of such data retrieval system prevent precise control of which data is actually recovered (e.g.


In the deterministic network calculus, dependence between .ows and servers is not taken into account since the analysis is based on the worst case.

for the stochastic network calculus, since tra.c processes and service processes are generally stochastic processes, it is natural to analyze cases where these processes are independent so that improved results may be obtained.


The idea is somewhat similar to [14] where Expectation Maximization (EM) is used to jointly estimate the location as well as device power level.

the system architecture in [14] is different from ours where sniffers are deployed to locate a mobile client.


As a consequence, the response time of the short .ows under FIFO is a function of both the IP level capacity of the access point and the losses they experience, which would lead to underestimate the IP level capacity.

under LASTOTAL, the response time of the short .ows is almost exclusively a function of the IP level capacity.


Also Bohacek and Sridhara [6] address the issue of the relationship between the mobility of nodes in ad-hoc networks and the resulting connectivity graph properties.

they focus on pedestrian mobility and on the effects of propagation on indoor users isolation, with limited attention to vehicular mobility.


For such networks, remote peering is just an extra option for bypassing their transit providers.

there are also networks with global tra.c that is too small in volume to justify the costs of extending their own infrastructures.


The drawback is that it may take a signi.cant amount of time until the new target size is reached (increasing a view size by s(n)will take r(n)· .time units).

maintaining a large view size all the time may be wasteful in case such a large view is typically not required or may even be impossible, if the node s memory is limited.


To perform network experiments, researchers often use a collection of commodity Linux machines as tra.c generators.

creating a large number of connections in order to accurately model the tra.c shape in networks with thousands of .ows is di.cult for several reasons.


On one hand, supercapacitors voltage level is refreshed within each radio mode change.

because a radio mode can be longer than few milliseconds, refreshments are also time schedule.


The signal is strongest when the ferry is close to land (Nesodden at the start of the path, and Aker Brygge in downtown Oslo) with observed average bandwidths above 2 Mbit/s.

the signal conditions far from land are usually problematic.


All these research efforts take into consideration the severe resource constraints of sensor networks, especially, energy and communication constraint, and their unattended deployment potentially in harsh environments.

this work does not deal with uncertainty in sensor data due to random noise.


Modeling Steady-state and Transient Behaviors of User Mobility: Formulation, Analysis, and Application  * Jong-Kwon Lee Jennifer C. Hou Ubiquitous Computing Laboratory (UCL) Department of Computer Science IBM Korea University of Illinois Seoul, Korea Urbana, IL 61801 jkwlee@kr.ibm.com jhou@cs.uiuc.edu ABSTRACT Recent studies on mobility modeling have focused on characterizing user mobility from real traces of wireless LANs (WLANs) and creating mobility models based on such characterization.

most of the work does not study how user mobility is correlated in time at di.erent time scales.


3http://sindice.com Graphs of such size can be created, processed, and iterated by our infrastructure in reasonable time, i.e., within a time range of 300ms.

the performance of the system signi.cantly drops when graphs containing more than several hundred triples are being processed (e.g., larger replicated data sets).


This constraint is typically imposed per time slot t.Thus it is not a simple matter to synthetically construct inputs to the gravity model: the inputs at each timestep are causally constrained, in a complex way.

the set of time-varying inputs {Ai(t)} to the stable-fP model are not causally related.


The models presented in this paper are based on the KW SIS epidemic models for homogeneous and Erd¨os-R´enyi networks.

we can also incorporate infection delay and user vigilance into other SIS (or SIR) models such as the ones presented by Pastor-Satorras et al.


This estimate is used to compute the log likelihood probabili    I Q Down-Conversion FPGA Data Buffers Figure 5: Radio board receiver path ties that serve as the input to the decoders, and thus an accurate estimation is important for the iterative (LDPC) decoder performance.

accurate estimation of the noise variance can be a challenging and complex task, since there are many sources of noise in a hardware implementation.


CONCLUSION The results seem to indicate that acting as a slave to the root zone results in a saving in the number of packets and queries involving the root servers.

it is not clear that it results in a reduction in the byte volume of tra.c; if anything the total volume of tra.c seems to have increased.


The receiver waking up earlier than the transmitter will be costly in terms of energy consumption.

the receiver being later than the transmitter will cause the transmitter to transmit more iterations of data-listen cycles, which is more costly than the receiver being early.


In this way, functionality of the overlay network is located at the peers.

the construction and use of overlay networks introduce sub-optimal aspects in the system operation.


2.1 Flexible Link Migration In its most basic form, a link at the IP layer corresponds to a direct physical link (e.g., a cable), making link migration hard as it involves physically moving link end point(s).

in practice, what appears as a direct link at the IP layer often corresponds to a series of connections through di.erent network elements at the transport layer.


Note that linear programming duality has also been exploited in recent research on oblivious routing [3, 39].

[3, 39] require O(|V|·|E|2) constraints, which is much higher than (7).


), nodes either proactively select neighbors to be rebroadcast hosts or reactively determine whether to rebroadcast based upon location information about their 2-hop neighborhood.

it is difficult to maintain this information in a high mobility environment.


Kotnik et al [12, 14] modulate data based on the autoregressive speech model and pass it through HR, FR and EFR codecs.

they achieve very low throughputs and high error rates; for example at 533bps, the BER isover25%.


Spatial diversity can also be exploited with collaboration among densely deployed APs [12, 13, 21].

these approaches can only improve the reliability of a single frame transmission; while SAM enables spatial multi-access and improves network capacity by allowing concurrent transmissions.


Thus, Proposition 3.9 can not provide a guarantee that a multi-parent customer can improve an node s TM completionability.

in practice there are a number of ways inwhich the .ows sent by the multi-parent node through the ob server may contribute to TM completion ability.


For instance, a single Query Round could be performed using HS mode, with retry ACKs being turned o.. Based on the rate of error, the reader could make an informed decision as to what up-link encoding to use for the next round to read the remainder of the tags.

as the result of a given round determines the tags that are active in subsequent rounds, an analysis of such schemes cannot be done based on our data.


Since it is conceivable that multiple MiniBricks may send messages to a single SmartBrick, a low-power MAC scheme to manage the communication channel is also necessary.

the design of such a MAC scheme is not considered here.


Such a bargain procedure can be directly realized on the Intemet.

it is inefficient for it may require many rounds of interaction between the seller and customer.


1: procedure Estimate delay(flow, SDS) 2: Nmin = 8 3: for i=1, R do 4: j. hash(i,flow) .

compute ith hash 5: if SDS[i][j].N <Nmin then 6: Nmin = SDS[i][j].N 7: Smin = SDS[i][j].S 8: end if 9: end for 10: return Smin/Nmin 11: end procedure Figure 3: SDS Delay estimation algorithm in practice, rows cannot be large enough, and thereisanon-zeroprobability of several .owscolliding(i.e., hashing tothesamecellinoneor morerows).