Despite this dual-actor landscape [14, 20], there are already three mainbusiness roles at play in the current Internet: The (Physical) Infrastructure Provider (PIP), which owns and manages an underlaying physical infrastructure (called substrate ); the connectivity provider, which provides bit-pipes and end-to-end connectivity to end-users; and the service provider, which offers application, data and content services to end-users.

the distinction between these roles has often been hidden inside a single company.


Improving TCP Smoothness by Synchronized and Measurement-based Congestion Avoidance Chi Zhang Vassilis Tsaoussidis College of Computer Science College of Computer Science Northeastern University Northeastern University Boston, MA 20115 Boston, MA 20115 czhang@ccs.neu.edu vassilis@ccs.neu.edu ABSTRACT In this paper, we observe that although multiplicative decrease is necessary to accomplish fairness in congestion control, it does not inevitably sacrifice system throughput, as long as the system operates between the knee and the cliff, according to an equation.

even when the system throughput is relatively stable, end users of real-time applications do not necessarily experience a smooth traffic, mainly caused by the unsynchronized window adjustments due to random congestion indications.


In practice, a node may not always move at a constant velocity.

it is common that a node may travel at a constant velocity for some time before it changes direction or speed.


The mean delays of X1 and X2 are still about 1s and 3s respectively.

replication  Figure 4: Distributions with more values below the mean have lower predictability results in a mean delay of about 0.2s, a 5× improvement compared to the shortest path forwarding.


In the original de.nition, the connection between two hosts is failed if the host cannot establish a connection with another host after sending four or more tcp SYN packets.

this heuristic with the original de.nition cannot identify any bittorrent peer at all in our test.


Ad clips are usually served by dedicated ad servers outside the content system, while .ag clips are usually served by the same server serving program content.

both ad and .ag media tra.c is extraneous to users of the media system, and do not re.ect the real user access pattern.


On the positive side, this approach has the bene.t of greatly reducing the impact of network congestion and channel unreliability.

buffering also increases delay as the receiver cannot start playing the video immediately.


Another observation is that the further two nodes are, the higher the proportion of erratic movements (all movements that are neither birth, nor death, nor sequential).


We can rewrite it as P (S1 + n1=0ION s0 + Z ..8 n1 ).

z], we n1=0I ON since E[S1] » E[ can assume that Z is negligible.


The impact, however, is limited because the peer has to be in a small region near the user.

our measurements in busy walkways (§3.2) show that groups of moving pedestrians have a heavier impact on connectivity.


In order to use sleep modes intelligently, several recent studies [11 13] have been proposed.

serverside energy-e.cient computing has recently been a focus, because 1.5% of the total US electricity is consumed by servers and data centers [14].


Alamouti code, with two transmitting antennas and a single receiving antenna, provides a diversity gain of two with no spatial gain, while with two receiving antennas the diversity gain is four.

spatial multiplexing gives a spatial gain depending on the number of parallel streams transmitted and a unit diversity gain.


An ideal scenario would be to assign a physical NIC to each virtual machine.

the number of I/O slots available on a machine is Copyright 2009 Sun Microsystems, Inc. VISA 09, August 17, 2009, Barcelona, Spain.


The horizontal line in Figure 4 is indicative of this.

the opportunistic work-distribution algorithm is capable of using nodes in the set G as long as their T costs are not signi.cantly above the admissible cost, TC.


A value of 1 means that the .lter implementation  (a) nodes (b) links Figure 10: Topology information missed missed all nodes and links when compared to the list implementation.

a value of 0 mean that there is no loss, and all nodes and links discovered by the list implementation are discovered by the .lter implementation.


aiting time before starting the highlight scene can be reduced by increasing the available bandwidth for delivering it.

since the available bandwidth for delivering the main program becomes relatively short, the waiting time between fnishing the highlight scene and starting the main program increases signifcantly and the total waiting time may increase.


We note that by data plane performance, we refer to IP packet forwarding, and do not imply that tunnels are not present or have no impact14 .

as we discuss next, tunnels are unlikely to be present in the primary data set that we use to validate H1.


Clearly, no linear separator exists in the input space.

as shown in the lower half of the Figure, the feature space de.ned by the kernel transformation F yields a separator.


Usually, the damage caused by active attacks is more severe than that caused by passive attacks.

active attacks are easier to detect since their actions can be tracked based on the anomalies they cause in the network.


For example, if in each second a node sleeps for half a second and becomes active for the other half, its duty cycle (and hence energy consumption) is reduced by 50%.

this protocol caters for networks with near real-time use where the environment or target requires to be monitored very frequently (every few seconds).


All in all, we have 253, 218, 206, and 299 patterns for Facebook, Hi5, LinkedIn, and StudiVZ, respectively.

even if an OSN restructures its Web site they usually do so in small steps.


It was proved in [4] that the HOL blocking limits the switch s v maximum throughput to about 2 - 2 58.6%.

the VOQ bu.ering maintains a (logically) separate queue for each output port at each input port, so that a packet will no longer be held up by another packet ahead of it that goes to a di.erent output port.


Our performance evaluation showed that medium-access aware RA strategies such as GORA, in which every station attemptstosel.shly maximizeitsgoodput, actually result in a degradation of the overall network performance.

simple legacy RA techniques such as MBLAS, in which every station chooses the PHY ratebased solely onitsSignal toNoise ratio, are much more robust and, on average, result in better performance.


In such a declaratory (rather than negotiation-based) approach, one risks sending lengthy Compliance headers, listing lots of extension identi.ers.

while there might be many registered extensions, in practice most implementations would support one of a relatively small number of distinct subsets of extensions.


Pure pro-active protocols may not fit to WSNs, where nodes move a lot, because of the high traffic overhead caused by the continuous updating of the network information.

pure re-active protocols may also have their problems; extreme delays and excessive control traffic, may make them unfit for certain applications (e.g.


This scheme is similar to CtS in that it uses the time interval to transmit information.

the timing channel approach is primarily proposed for secure communication, and hence throughput and energy consumption are not major concerns.


[4] used PRISM to introduce a Continuous Time Markov Chain representation of the Kaminsky attack and the proposed fix, and to perform the required probabilistic model checking.

their analysis of attack difficulty largely target at basic poisoning model which factors TTL of the target domain while Kaminskyclass poisoning inherently has no "wait penalty" for poisoning failure.


For example, if the failure caused a loss of reachability to a destination network, the router will generate a withdrawal message, listing the network pre.xes that have become unreachable.

if the failure simply causes a path change (or if the router learns of a previously unknown destination), then an announcement is generated containing a set of network pre.xes and associated path attributes.


All the players in the game have complete knowledge about both channels and the strategy adopted by the adversary.

neither the legitimate transmitter nor the jammer can observe the signal transmitted by the other.


The combination of the validity and well connected properties form the basics for any desirable scheduling function in any grid formation obeying the grid/mesh transmission range inequality.1 Validity ensures that there will be no collisions on one hand, and that whenever a node sends a message, some other node will be listening for these messages.

well connected means that it is possible to .nd a routing scheme that will deliver messages between any pair of nodes.


A TTP that knows the content of the messages requires a huge grade of dependency on the confidence in a third party.

a TTP that does not know the contents presents a lesser grade of dependency as regards the trust we have to deposit in the third party.


Still, a little over 10% of the population experienced false reject rate of 10% or more, and about 20% of the population had false reject rate above 5%.

80% of the population still only saw 5% or lower false reject rate.


Here, Txyielding is that a certain link passes on an opportunity to establish the link as it creates too much interference to other links which have higher priority than itself.

rxyielding means that the link gives up the communication because of intolerable interference from other links [3].


As shown in Table 5, 59.5% of static .ows are HTTP and POP3.

these two applications contribute merely 13.7% to the roaming .ows.


Algorithmic Framework Most previous works focus on the algorithms of finding HHHs.

since we are mostly concerned with integrating such algorithms with network measurement systems where traffic data are often collected in fixed time interval, we have to consider the relationships between each measurement round and make full use of the relations between different intervals.


Earlier in this section, we described techniques to automatically detect when the download of a page breaks due to disabling of cookies or JavaScript.

a more subjective type of impact is when the technique causes a degradation in the quality of the page.


This is aligned with our expectation that long-running high-throughput .ows enable the scheduler to shift traf.c to the more energy ef.cient 3G interface for that throughput area.

the main point is that MDP always keeps the gap to the omniscient ORACLE very small.


In other words, the safety interval should be shared by nodes within the same contention domain as well as nodes hidden from them, because hidden nodes may also transmit their beacons in the safety interval.

existing protocols do not consider the presence of hidden nodes when they calculate the safety interval.


Our solution to this is firstly to use a unique conversation identifier between the auctioneer and each agent, in the style of the previous section.

in the English Auction Protocol, the conversation identifier is parameterised by the sending agent with a vector timestamp [11] which will enable the agents to determine potential causality.


This is because, in HCDD, there is only single structure used to maintain the routing information even if there are multiple source nodes in the network.

in the grid method, each source node builds an independent structure for itself, and, hence, the overhead of location update procedure would signi.cantly increase with the number of source  number of source nodes Two-level(1,1) One-level(1) Grid-based(50) 60 sources 1.9648 (joule) 4.5461 (joule) 19.7699 (joule) 100 sources 1.4017 (joule) 4.0113 (joule) 24.6024 (joule)  Figure 6: Number of sources vs. Network lifetime Figure 7: Comparison of di.erent schemes Table 1: Overhead comparison nodes.


According to our previous results, these metrics do not present the shortcomings of DSD and DTD.

the comparative study presented in[8,9] was onlybased on .rstgeneration mobility models (i.e., synthetic models), whichare not realistic[28].


In [12], the authors propose to use power lines for clock calibration.

due to dramatically decay, the periodical signals can only be detected in the vicinity of power lines.


For each VP, we tracerouted to the .rst (.1) address in each of the 465,944 non-overlapping pre.xes observed by Route-Views collector rv2, used BGP data to map the encountered IP addresses to ASes, and inferred an interdomain link when we observed the .rst address in a traceroute path that maps to an AS outside the VP s hosting network.

this method may not correctly identify the border routers, or their owners, depending on how interfaces are numbered.


In this case, if we further assume synchronized data collection, i.e., all the sources start their collection at the same time, we can achieve the largest time-overlap of the packets, and thus maximize the rate of each source node.

in practice, the time-offsets of the packets from different nodes may be time-varying, due to the dynamic join (leave) of sensor nodes, and the oscillation of the rates caused by the variation of the environment as well as the underlying MAC layer scheduling.


This is because LWB keeps no topology-dependent state: as long as the network is connected, LWB is oblivious to topology changes.

bCP and CTP deliver fewer packets when the sink moves: they need to constantly recon.gure state that depends on a node s current neighbors and connectivity.


Once purchased, a unit of data can be treated in the same way as the budgets IMP currently considers, since there are no refunds for unused data and partially spent units are generally rounded up to the next full unit for billing.

we would also need to consider the monetary cost of each data increment and also incorporate some notion of how much the user is willing to spend, which would require direct input from the user.


For scenario (i), if we apply the TZ cluster construction on (V, E), we end up with a set A with the required cardinality, and cluster CA(w) s such that |CA(w)| = O(.n log(n)).

because we constructed A and CA using exclusively (V, E), |CA(w)| does not account for any mobile nodes.


This implies that we can wake up nodes at any location of our choice.

this assumptions may not be true in practice.


This greedy choice may be sub-optimal in that the chosen tree may be the only suitable choice for another tree which would now remain unmerged.

we .nd that the greedy choice works well in practice because there are not many suitable Category i-1 trees from which to choose.


Given any solution to the 2-spanner problem, we set the push set (resp., pull set) to be the set of neighbors of the node in the solution subgraph; the resulting cost is twice the cost of the subgraph.

any solution of push and pull sets for the data dissemination problem yields a 2-spanner of at most half the cost.


it is important to note (the maximum angular gap required): .


They will surely bene.t meSDN , and we look forward to seeing such new knobs.

even with those new knobs in the driver, we believe pTDMA scheduling intelligence is better to reside outside the WiFi driver/stack and rather in the meSDN global or local controller where information about user applications and other devises is available.


This is re.ected in the wireless target channel capacities in Figure 5, where the download to the good location consistently yields a target link capacity of 54 Mbps regardless of the location of host B.

when host B is at a bad location its average target channel capacity falls below 11 Mbps.


Accommodating nomadic usage with the statically configured IP address procedure originally used in the Internet is very difficult.

nomadic usage is easily handled by dynamic address allocation, introduced in the mid 1990's and now ubiquitous, to simplify IP subnet configuration [4][9].


The system then oscillates as shown in Figure 11.

the system has no dispute ring; in particular, the dispute wheel depicted in Figure 10(b) cannot be reduced to a dispute ring.


This result forms a strong di.erence to the standard worst case competitive model for oblivious routing in which for some newtorks no algorithm v with competitive ratio o( n) can be obtained.

we show that for some networks no log n oblivious routing algorithm can be o( ) competitive log log n even with constant probability.


The NCBP for both frameworks increases as the call arrival rate increases.

the NCBP in the case of the QoS-AMS 0.18 0.16 0.14 Figure 6: The effect of varying ß on NCBP 0.12 framework is lower than that of BAF.


Taking into account these results, although the idea of using flat routing protocols could be considered in small networks (< 50 nodes more or less), using hierarchical routing will produce almost the same performance.

when the network is bigger (> 50 nodes), we find clear scalability problems in OLSR protocol, whereas in the HOLSR protocol a lineal growth is maintained in the overhead parameter.


Forexample,fora3 transmittersystem,we .nd thatmultiplexingschemes(netMIMO)yield thebestperformancefor static users withlarge coherencetimes withgains ashigh as 69.84%.

when applied to mobile users and even static users with small coherencetimes,itdegradesperformance by as much as 71.4%.


The scheme can be used to pair devices with minimal hardware interfaces (only an LED and a button are required) using one of the SAS protocol.

as we discuss in the next section and as indicated in the results of [17], the scheme is a bit slow.


([11]) suggest that cluster-based topologies could be rather efficient, again, in eliminating redundant transmissions in the context of spatial correlation aware routing.

our scheme C utilizes transmission across the spatially correlated nodes.


We had hoped to achieve this effect by matching on these .ags and using OpenFlow to put these packets in a higher priority queue on the monitor ports, but OpenFlow does not currently allow for matching on TCP .ags.

types of traf.c OpenFlow can match on could be given higher priority sampling with this method.


PRINCIPLE AND RESERVATION PROCEDURE IN HO-RSVP 4.1 HO-RSVP MODEL In a mobility environment, where both sender and receiver are mobile nodes, the path between the two endpoints changes frequently.

there must be some unchanged segments in the signal flow paths between sender and receiver.


More details about this method are given in Section 3.3.

the introduction of multiple trees adds extra memory accesses which decrease throughput.


GPUs have already been proposed to accelerate di.erent networkingworkloads [8, 14, 11].

to the best of our knowledge, our work is the .rst to exploit GPUs for indexing in the context of highperformance packet recording systems.


This helps them cope with multi-path by adaptively changing their radiation pattern to accommodate the scattering resulting from multipath.

this requires some feedback mechanism to help adjust the weights.


When the incoming budget, I(t), is relatively constant over time the price is stable.

when the input budget constantly changes by a large amount (e.g., due to .ow departures and arrivals or budget assignment changes), the price will also .uctuate.


Thus, exploiting multi-radio capabilities may help improve the e.ciency and e.cacy of multicast communications in the 4-th generation LTE networks.

developing and testing new protocols and mechanisms in real LTE networks is limited and LTE eMBMS is yet to be deployed.


Therefore, we do not have to modify existing web browsers or implement a new one.

for ease of automating experiments, we implement a minimal browser application (totalling 150 lines of code) that is simply a wrapper around QtWebPage to load the webpages.


Concerning network layer attacks, such as Denial-Of-Service (DOS) and Distributed-DOS (D-DOS) attacks [10], the structure of the PN and PN-F offers a protection to the internal parts of the network.

nodes in the edge of the networks such as gateways are still exposed to this kind of attacks.


We expect the DHCP broadcast load to be similar to the NLA-HERE load, which (in section 4.2) we argued is just a small percentage of net work capacity.

other tenant multicasts and broadcasts (particularly from malicious,buggy, or inef.cient VMs) could becomea problem.


Scap shares similar goals with Libnids and Stream5.

previous works treat TCP stream reassembly as a necessity [50], mostly for the avoidance of evasion attacks against intrusion detection systems [14,19,51].


On the other hand, the communication requirements and hardware capabilities of an individual cognitive radio varies in a heterogeneous network and so the overhead of sequence based spectrum mapping may be counterproductive for some nodes particularly those having sporadic communication needs.

since a channel s availability can be represented using single bit, the real-time spectrum map dissemination is possible without much overhead and can take place on the common control channel or piggybacking with the packets on data channel.


present a MAC protocol that exploits the availability of multiple channels.

they change channel assignment in a fast time scale on a per-packet basis which may not work with existing commodity hardware.


The simplest sensor selection scheme is to choose the sensor set randomly from among the sets that meet application QoS requirements.

random selection cannot optimize the network lifetime by selectively using the sensors.


The .exible spectrum acquisition gives a particular provider the chance to easily adapt its system capacity to .t end users demand.

the competition among several providers for both spectrum and end users complicates the situation.


This result shows that SafeGuard prevents packets from being trapped in micro-loops, as packets at most take one detour to reach their destinations.

the vanilla IP forwarding with OSPF can have amplifying factors greater than 50.


In health care or assisted living, an intelligent sensor network may automatically evaluate the health status of residents, and react when they are in danger [13, 14, 15].

existing classi.cation techniques designed for sensor networks fail to take into account the fact that in many applications of sensor networks, the amount of labeled training data is usually small.


Scheduling algorithms delivering strong performance guarantees are certainly important, especially considering that nowadays many broadband based multimedia applications have quality of service (QoS) requirements.

it is also worth studying scheduling algorithms that are simple and easy to implement.


The VisSec community uses the mind s spatial reasoning capability to recognize anomalies and patterns that cannot be easily captured through algorithms and computation.

little work has been done in using visualization to help cyber security detect DNS tunnels.


An alternate approach to the complete edge selection rule is to remove those edges connecting vertices with a large time di.erences.

we should only remove those vertices that retain the subgraph s unique embeddability.


A good analysis must include tests over large networks, using real devices and a considerable number of users.

how to test in these scenarios with many users is an open question.


6.5 Energy Overheads There was a linear increase in processor load and memory requirement with number of clients in power save mode.

with up to 8 players in power save mode, there was less than 3% increase in processor load and memory.


It is suitable to authenticate program updates since the program image is broadcast in packets.

µTELSA requires loose time synchronization among sensor nodes which leads to additional complexity.


The general consensus that can be drawn from the aforementioned related work is that adaptive retransmission improves video and is necessary for real-time video streaming.

none of these studies considered the current H.264 Advanced Video Coding (H.264/AVC) standard.


This extra encapsulation, which is for a good reason of traversing NATs, adds extra overhead of encapsulation and decapsulation.

iSATAP is most recent among its contenders and involve least number of intermediate devices to route traffic.


0or l0 .0), the .eld approaches the trivial case of completely dependent with no need for communications.

as long as the .eld is not anywhere close to this, for a large range HDB remains asymptotically optimal:.


The .gure shows that even though the di.erence in WiFi availability in only 12%, the corresponding increasing in 3G savings is much higher.

this is true only for large delay tolerance thresholds.


At low packet loss, rateless Deluge performs near optimal while the other two versions perform similarly.

as packet loss increases, original Deluge requires signi.cantly more data packets to disseminate the image.


For the baseline scenario in Figure 7(a), the constraint is the available board area: as poff increases, more routers are required in order to accommodate the increasing off-board destined traffic.

they can not be accommodated due to OPCB area constraints.


Second, EM-MAC achieves quick and accurate multichannel rendezvous, thereby minimizing sender idle listening and overhearing.

the other protocols are not as ef.cient in utilizing the channel resources.


However, current ON approaches lack the ability to autonomically con.gure a system consisting of both clusters and workstations in a scalable manner.

previous work on this topic [11, 13], analyzed the use of Peer-to-Peer (P2P) VN interfaces and the prospects of using dynamic host con.gurationprotocol(DHCP) and addresslookup through the use of adistributedhashtable(DHT).alimitation of this approach was the need toincurON routing overheadfor allVNpackets,including thosedestined to LANhosts.


This is because Optimal exploits the users sharing behavior and opportunistic contacts to e.ciently disseminate up-to-date content.

optimal oblivious ignores these factors and simply relies on relative di.erences in content generation rates when making transmission choices.


The data sizes for the seg 2K-1 ments are J, 2J, 22J, ..., J.

since the data size of the Kth channel becomes half of the data, clients may experience waiting time and interruptions.


When the number of end stations is small, the AHMAC operates under contention mode since the DCF can accommodate the tra.c forwarded from/to the Internet.

if the number of end stations is larger than the capacity that the DCF can serve, the AHMAC operates in PCF-enabled mode.


That being said, we do not envision these SLS-like services replacing forums like Flickr or YouTube, which have proven to be de-facto .le stores for widely sharing information.

these SLS-like services could be useful for providing secure hosting for information that is to be shared with a more limited audience.


Many solutions to this problem have been proposed ranging from premium paid services providing dedicated channels with guaranteed communication parameters, to higher-priority per packet service by specifically classifying and marking packets in a limited set of classes, to which higher forwarding priority is given at each participating router.

a large amount of this type of traffic is not directed through premium service channels.


We have sketched the system architecture, as well as implemented a prototype as a plugin to Firefox browser.

our mechanisms require re.nement which we are undertaking as part of our future work.


Processing time per packet also increases with the number of MT nodes in each packet.

the exponential growth of the number of parallel S2 transmissions per S1 helps the signer to achieve a better adaptation to its available bandwidth, albeit at an increased computational cost.


The CDF of packet interarrival times for RealPlayer has a gradual slope as packets arrive over all ranges of the normalized interarrival times.

the CDF of packet interarrival times for MediaPlayer is quite steep around a normalized interarrival time of 1, indicating that most packets arrive at constant time intervals.


Landmark [28] also automatically con.gures hierarchy onto a physical topology and relabels as a result of topology changes for ad hoc wireless networks.

landmark s hierarchy levels are de.ned such that even small topology changes (e.g.


The performance guarantee of Algorithm BestNeighborhoodFirst is very dif.cult to prove for arbitrary topologies.

our problem can be viewed as a much more complex version of .nding maximum weight independent sets (MWIS) in a graph.


The successor, obfs3 [21], uses a customised Di.e-Hellman handshake to solve this problem.

both, obfs2 and obfs3 can be actively probed and do not disguise .ow prop erties.


The combination of coverage and connectivity is a special requirement introduced by sensor networks that integrate multi-hop wireless communication and sensing capabilities into a single platform.

traditional mobile ad hoc networks comprised of laptops only need to maintain network connectivity.


The latter is useful for systems for which the kernel modi.cation is not available.

even this does not fully address the problem.


A reclustering chain reaction is a very expensive operation in terms of message and time complexities.

dISCA is able to eliminate this scenario successfully due to the unique feature of the leadership duration concept.


Mathematically, this problem can be formulated as a linear programming (LP) problem (see Section 2.2) within which the objective function is de.ned as the sum of rates over all the nodes in the network and the constraints are: (1) .ow balance is preserved at each node, and (2) the energy constraint at each node can be met for the given network lifetime requirement.

the solution to this problem shows (see Section 5) that although the network capacity (i.e., the sum of bit rates over all nodes) is maximized, there exists a severe bias in the rate allocation among the nodes.


Using unicast communication requires unique messages for each sensor used by each controller.

the broadcast nature of wireless communication, makes it possible to improve ef.ciency by allowing any interested node within a shared communication area to receive the same information.


This explains why they reduce the FCT tail but worsen the median.

nE T AG G improves the performance for all .ows by reducing the traf.c of the aggregatable .ows.


Delaying flash writes may cause data loss if the email client or the smartphone crashes before the cached data are written to flash storage.

modern smartphone operating sys-tems including Windows Phone, Android and iOS all run each application in a separate protection domain (i.e., the so called application based security model ).


V (t) with |X| < k. We want to extend the de.nition of k-connectivity to a TPSO considering all topics in T .

given a parameter k, |V (t) | might be smaller than k for some topic t .


For instance, the FEDEntity block implements all of the VHDL entities, so it consumes 115 LCs.

because the FEDEntity only implements other VHDL entities, it does not require any logic, only registers that are used to store date as it is passed between the other entities.


The advantage of SAM is that it is integrated with other systems used for grid operations in EGEE and numerous sensors have been developed for checking EGEE-specific grid services.

sAM cannot be utilized for other purposes, e.g.


Scheduled access methods [7, 16, 19, 25, 27, 29, 31] can operate under transceiver and channel constraints and can address starvation by coordinating transmissions across multiple channels (be it time slots, frequency bands, or spread spectrum codes) in an optimal manner.

such techniques typically require global knowledge of topology and traf.c requirements as well as some form of infrastructure support: either global time slot synchronization (TDMA) or pre-distribution of codes (CDMA).


It comes hence straightforward to imagine players exploiting ad-hoc connectivity among their devices to support game interactivity.

this is not as simple as it may seem; in particular, we can identify the following three major issues.


Thus, DRAS.264 prevents all MAC frames containing slice headers from being dropped as long as they are within their corresponding playout deadlines.

2RTS/CTS is disabled for real-time video streaming if Tf rm exceeds Df rm , then the drop noti.cation is permitted to inform the Network Layer.


When there is only one communication session, the average delivery of SPEED is lower than other two protocols since SPEED focuses on finding high speed paths for data delivery.

when the number of communication sessions exceeds 2, the average delivery delay of SPEED significantly increases than other protocols.


Publishing should advertise resource descriptions so to allow others toadequatelyrecognize and classify them.

thesedescriptions should not compromise the security of the mobiledeviceowning the resource.


Related Works In [1] and [11] a database approach is proposed for designing WSNs.

our work adopts a service-based approach, in which interactions between applications and the network are based on a consumer-provider relationship.


Heterogeneity: We believe that Rainbow has potential to tame heterogeneity.

rainbow suffers from degradation of link utilization in face of heterogeneous receivers, as shown in section 4.2.3, because of its compli- cated packet reordering behavior.


Balancing Authentication and Location Privacy in Cooperative Authentication Liu Licai1, 2, Guo Yunchuan2, Yin Lihua2 and Sun Yan1, 2 1Beijing University of Posts and Telecommunications, Beijing, China 2Institute of Information Engineering, Chinese Academy of Sciences, Beijing, China { liulicai, guoyunchuan, yinlihua, sunyan }@nelmail.iie.ac.cn ABSTRACT In MANET, the cooperative authentication mechanism requires the cooperation of the neighbor nodes and significantly enhances the authentication probability.

it exposes location privacy of neighbor nodes and is costly.


Thus, intelligent path .nding algorithms [12, 13, 24] are required to manage aspects such as e.ciency, isolation, load balancing, QoS, etc.

for the purposes of this paper, our implementation Figure 2: Topology graph generation  Figure 3: Hybrid-controller working .ow on adopts a simple shortest path algorithm.


Note that more popularity of broadcast contents (smaller i) increases Ns as Figure 2 illustrates.

consider the average number of waste resource blocks Nw, represented in the following proposition.


Since in the infrastructure mode of the 802.11 protocol all traf.c goes through the AP, one may think that placing all sniffers near the AP should maximize the capture performance.

our experiments showed that the capture performance of To-AP traf.c 6We use the MAC time of the received frame, which is available in Prism2 header in the captured frame, as the local timestamp at each machine.


OpenFlow MPLS and the Open Source Label Switched Router James Kempf, Scott Whyte, Jonathan Ellithorpe, Peyman Kazemian, Mart Haitjema, Neda Beheshti, Stephen Stuart, Howard Green james.kempf@ericsson.com, swhyte@google.com, jdellit@stanford.edu, peyman.kazemian@stanford.edu, mah5@cec.wustl.edu, neda.beheshti@ericsson.com, sstuart@google.com, howard.green@ericsson.com ABSTRACT Multiprotocol Label Switching (MPLS) [3] is a protocol widely used in commercial operator networks to forward packets by matching link-specific labels in the packet header to outgoing links rather than through standard IP longest prefix matching.

in existing networks, MPLS is implemented by full IP routers, since the MPLS control plane protocols such as LDP [8] utilize IP routing to set up the label switched paths, even though the MPLS data plane does not require IP routing.


From an ISP viewpoint OSNs currently contribute a lot less than peer-to-peer applications in terms of bytes.

oSNs might add features that increase the per-user bandwidth demand.


This is because, in the case of a failure, the performance of 1+1 and network coding will not be affected ,i.e., no more time slots are required.

the performance of 1:N will get worse, because it will consume more time slots to do the re-routing.


Nevertheless, PCF has not been widely implemented because of its unnecessary transmission of CF-Poll frames and di.culty in maintaining a polling list [16].

since MPs in WMNs rarely move and WMNs usually carry a lot of tra.c, a polling list can be easily managed and unnecessary transmissions of CF-Poll frames can be minimized.


However, there was little interest displayed by the students for notebook computers and the student notebook purchasing operations were terminated.

feedback was strong to continue notebook computers for the faculty and since 1997 every faculty member has been issued a notebook computer.


Tree structures are optimal data gathering structures in a number of cases.

constructing an optimal tree is an NP-Hard problem in many of these cases.


By spreading out the information to other nodes the probability of meeting the sink increases and consequently the delay of delivery decreases.

faster nodes that move towards the sink, can bene.t of their high mobility and decide to ferry data or to disseminate data while using a smaller value for ß.


Although Angle Based has a more intelligent delay function than Counter Based, its forwarding condition causes most of the nodes near the edge of a transmission range to rebroadcast because the condition is difficult to be invalidated for these nodes.

our Cell Broadcast takes advantage of the fact that additional rebroadcasts besides the 4 corner rebroadcasts do not provide much additional coverage (as described in Section 2.4).


The signal leakage also exacerbates the level of interference.

3D beamformingboundsthe interferenceregiontoamuchsmaller area and limits the impact of signal leakage.


Recent work from the systems and networking communities, for example, has focused on RDMA reads as a building block, because they bypass the remote network stack and CPU entirely for GETs [21, 8].

however, the HPC community has made wider use of messaging, both for key-value caches [14] and general communication [16].


In this case, the node where the deadend was reached performs an expanding ring search until a closer node is found (or a maximum TTL has been exceeded).7  3.2 Distributed Hash Table Above we described how packets are routed over (real or virtual) coordinates.

routing by itself is not suf.cient to use the system.


Memoryless relays can forward the message to the same next hop more than once, because they are not at all aware of what happened in the past.

memoryful relays possess this knowledge, and are able to refuse the custody of messages that they have already relayed.


8.2 Limited Availability Our testbed can be operated at 100% duty-cycle during only a few hours in the middle of day when direct sunlight is present.

a duty-cycle ranging from 20% to 40%, depending on the time of year, allows continuous operation.


Using a mobile connection such as 3G or WiMax, information can be uploaded to a central storage and retrieved from the same storage.

with the increasing number of devices generating data and the rates at which data is generated, the bandwidth requirements will quickly overwhelm the infrastructure, especially considering that those networks are alreadypushed tothelimitto serve existing mobileInternet access.


Strata requires correction between 1.33 to 1.39 for the same range.

the accuracy of the Min-wise estimator deteriorates rapidly for smaller delta values.


SNRP implements a similar mechanism as that in MSTBG.

unlike other algorithms that are centralized, SNRP is speci.cally tailored as a distributed and localized algorithm for WSNs.


Even when these flows fall in error, and are not using channel bandwidth, the scheduler must anticipate the end of their fade and the renewed con- nection with the data traffic.

in scenarios where these connections fail completely, the base station must be able to make a decision that the call has been terminated.


It can be seen that CGR produces average stretch very close to 1 in all cases, comparable with that of S4 and DRP.

other algorithms stretch grows steadily with K, reaching maximum at various points, before starting to decline.


This strategy works well when the tag population size either remains static or increases.

when the tag population decreases, the best choice is to re-execute TH for the subsequent scan.


This allows us to avoid problematic assumptions about how often a client can expect to .nd new data to download.

we did not model varying bandwidth or BitTorrent s tit-for-tat system.


This means that it is not feasible to probe the entire identi.er range for third-party applications due to the resulting costs for crawling and the fact that only a subset of these IDs are for apps.

facebook indexes all third-party applications that have reached more than 10 monthly active users in their search feature.


As we shall see in Section 3, our analysis applies to all these protocols.)

13 ASes with high customer degree & no providers 100 top ASes by customer degree & with providers Tier 3 Table 1: Tiers.


Most of these works followed a general approach by constructing a broadcast tree as well as a deterministic or randomized con.ict-aware transmission scheduling.

such approach is hardly to be applied in mobile ad hoc networks, since the network topology may change unpredictably over time, and the coordination among nodes are expensive.


Much research has been done on systems for large display walls, such as the PowerWall [12] and the In.nityWall [5].

many of these systems require that each display component of the wall be connected to a large SMP system.


[6] to show that systems with next-hop rankings always have at least one stable routing.

we also show that when BGP s protocol dynamics are taken into account, restricting each AS to only next-hop rankings does not guarantee that the routing system will be safe.


However, the system was operational, showing that even with present day hand-held devices, QoS Seeker technology operated well.

on such a small footprint device a more coherent design and integration of the GPS acquisition, VoIP application and the QoS Seeker technology would be of bene.t.


DEPLOYMENT SCENARIOS In Section 4.4 we presented upper bounds on the improvements in security from S*BGP deployment for choice of secure ASes S. We found that while only meagre improvements over origin authentication are possible in the security 3rd model, better results are possible in the security 2nd and 1st models.

achieving the bounds in Section 4.4 could require full S*BGP deployment at every AS.


If most jobs are small enough to .t within a rack, few jobs need to straddle the rack boundaries.

very few large jobs which need to cross the core of the network can be scheduled to run concurrently since each of them consumes a large number of VMs.


When examining scenarios where the client or the AP are the bottlenecks, such inaccuracies may be acceptable.

when 8 6 4 2 0 0 2 4 6 8 10 12 4 3 2 Error in Estimated Delay (%) Channel on which beaconsare decoded correctly Detected in 1 and 5 sec runs Detected only in 5 sec run 1 0 30 60 90 120 150 180 210 240 270 300 Delay Introduced at client (m sec) Figure 10: EDEN s accuracy of estimating the delay at a client these entities are not bottlenecks or when EDEN is examining a scenario with low delays or when contention is even worse (e.g., the contention delay can even be more than 20 msec in 802.11b), a better estimation is needed; we are currently exploring mechanisms to reduce such inaccuracies.


In our proposal, all hosts have proper parents and can receive at the rate which they desire by using the redefined degree parameters.

other methods have the described problem of improper relation in Figure 1, and some hosts can not be satisfied with the receiving rate.


Typically, each additional base station antenna provides a power gain (both by increasing the total transmit power and improving directionality), as well as a potential multiplexing gain (by increasing the possible number of users served simultaneously).

when zero-forcing, each additional antenna also increases the amount of data sent to the central processor, increasing transport and processing overhead.


This allows one to directly infer keys from the (modi.ed) sketch data structure without requiring a separate stream of keys.

this scheme also increases the update and estimation costs and additional research is required to make it more ef.cient.


It is worthy to note that secure device pairing methods are recent alternatives that do not assume pre-shared secrets, while enjoying higher usability (e.g., GDP [21, 20]).

they assumed the existence of some additional out-of-band (OOB) secure channel that facilitates human-aided veri.cation, which may not be intuitive to use.


On the other hand, it has no interest in removing links to major players.

it will try to establish links with the major players, and these will be formed if eq.


Each flow is initially connected with a value of 7 = 1, and will re- main at that level as long as communication is established.

as soon as the channel experiences error, the pa- rameter will be allowed to fade towards 0.


The main reason for this is to reduce the load on our test servers.

some clients may ignore the JS-test cookies and perform the test multiple times within 24 hours.


As a result, existing power studies for computing systems usually focused on other system components such as the CPUs, the memory, and the disks.

we should note that the power impact of adapters comes from not only themselves, but also their interactions with other system components, such as the CPUs and the memory.


The functions we next describe might be abstracted by an application-independent library.

since the library would be under a s control, and since some applications might want different behavior and thus elect not to use the library, we will describe the actions as performed by a, not by the library.


Game play is typically built around a client-server communication model, and the resulting traffic patterns have been well studied to date.

the discovery of available game servers is itself a client-server process.


This is an expected behavior and is not shown for the same purpose.

for the time to disseminate there is no clear winner.


On the contrary, if the relays selected based on this heuristic do not re.ect future forwarding probabilities, very long delays may be incurred.

using certain timeout and retransmission schemes, these long-delay messages might be masked out which makes the history approach more attractive over the others in networks with predictable node movement.


2.3 MDCube Design Overview BCube builds high capacity network structure using only COTS switches and commodity servers with multiple ports for better performance-to-price ratio [2].

bCube cannot directly scale out to millions of servers by adding more ports to servers and deploying more COTS switches.


.v .v Figure 4: Spatio-temporal data send mechanism.

in our scheme, the output .ow is indirectly controlled using ev.


The same assumptions are assumed for FMIPv6.

the LMA and the MAGs are replaced by a HA and ARs, respectively.


The metric used in BubbleRap to decide if node a needs to forward a copy to node b is (a) the global rank if the two nodes come from different clusters and (b) local rank if the two nodes are from the same cluster.

in our SNAMD schemes, we use (a) the delivery predictability [18] as the metric when the two nodes belong to the same cluster or (b) a node s estimated contact rate to a destination if the two nodes are from different clusters.


those ASes that appearinthe secondlistbutnotinthe.rstmayhave relatively more compromised hosts.


When the third packet P 3 arrives, the rule cache updater attempts to expand the .rst evolving.

the proposed rule con.icts with the original ruleset.


1, we can guarantee no ACK frames are corrupted by concurrent DATA frame transmissions.

we still have other types of collisions.


Reliability is easily achieved by using TCP in overlays.

overlays do not use network bandwidth e.ciently.


CONCLUSION Greedy forward routing is a localized and memoryless geographic routing.

it cannot guarantee the delivery of a packet from its source to its destination if the transmission of the nodes are not large enough.


Unfortunately, the bit rate information is not readily available for YouTube videos.

for the videos accessed on our campus network, we were able to estimate the encoded bit rate as the ratio of a video s .le size (obtained from the Content-Length: header) and its duration (retrieved using the YouTube API).


Most IM worms install backdoor programs to further exploit infected hosts.

to date such worms generally have not carried any damaging payload other than the replication engine.


And the source address of the inner IP header of the IP-in-IP encapsulated packet is the address of CN.

in NTLP protocol, the address of the signaling messages is the addresses of adjacent signaling peers.


The better a receiver s channel, the more data it can decode.

when data is encoded directly into pixels (as is the case for QR codes, for example), receivers receive either all data or none.


Otherwise, u (winner) maintains its state as a dominator, and sends a DOMINATOR message.

the winner must be connected through connector nodes to all dominators within three-hop distance by applying the CDS algorithm locally.


2Currently there is no limit to the number of paths that can be stored in each node s path cache .

it would be relatively straightforward to age path table entries, e.g., by recency, to limit path storage requirements.


If we are attempting to determine the minimum d such that all dK-graphs are similar to G, we can start with a small value of d, generate dK-graphs, and measure their distance from G. If the distance is too great, we can increase d and repeat the process.

to explore structural diversity among all dK-graphs, we must generate dKgraphs that are not random.


In the direct delivery scheme, as the name suggests, the source node delivers the message only on its encounter with the destination node.

eR is a .oodingbased protocol, that replicates messages on every new contact opportunity.


A more recent .ow cache scheme [4] uses a 4KB size cache that can be con.gured to store 611 concurrent .ows, and reports a cache miss ratio of 4.85% on a sample trace containing up to 567 concurrent .ows.

we will show in this paper that our rule caching approach can achieve superior performance than .ow caching ones, with orders of magnitude lower cache requirements.


Similarly, edit distance takes longer for large word lengths, and the number of test words.

it is independent of any database, hence the space requirements are smaller.


For small forwarding tables, computing the cross-producted .ow table is manageable.

for a large number of .ows, the cross product can grow nonpolynomially.


A : dec(M, key(B)) The inference rule fails to predict what happens when M = enc(X, key(B)).Inthis case, A would wind up sending a cleartext message X,butthisis becauseofthe actionof A s decryption operation,not becauseoftheapplicationofaninferencerulebythe intruder.Thus,theinferencerules are not complete.

althoughthereare subclassesofprotocolsforwhichgivensets ofinferencerules aresound(seeforexample[33,37]),this must be carefully worked out for each case.ifsuccessful, augmented inference rules have the advantage that they can be used with tools that do not support the equational theory that the inferencerules represent.


MOTIVATION AND ATTACK METHOD 2.1 Motivation In a SDN environment, the control plane can dynamically enforce .ow rules when the data plane requires, and it enables us to control the network e.ciently.

this kind of reactive-mode control can cause serious problem when there are too many requests from the data plane to the control plane.


With recent advances of network coding theory, many multirate multicast techniques using network coding have been proposed and they hold promises of improving information multicast e.ciency over the traditional application-layer multicast protocols.

all these network coding based multirate multicast solutions adopted a layered coding technique and involves computationally expensive optimization to decide the amount of information transmitted in each multicast layer.


ILLUSTRATIONS Remark may not be a valid data for an Egalitarian PS queue, since it may be that some entries in P are larger than 1.

it is always true that P g is a positive matrix with the same spectral radius as P .


As long as the popular contents are not very concentrated, the number of replicas is small.

when a is big, the number of replicas will increase.


3.3 Packet Spoo.ng After AMR meters have been installed, most customers and utilities trust the integrity of the collected meter readings, since AMR meters reduce human errors associated with the traditional analog meter collecting process.

such a trust relationship must be questioned, should a malicious attacker be able to forge packets containing arbitrary data and successfully deliver them into the provider s data collectors.


When the maximum node degree is bounded, polynomial algorithm with n O(d2) time complexity is known [18], where n is the number of nodes and d is the maximal node degree.

n O(d2) is too slowfor our problem since data centers can havemillions of devices [6] and the maximal node degree can be more than100[9].To thisend,wedeviseO2,afast one-to-one mapping engine.


As a result they are prone to select modified routes with either shortest hop-length or highest sequence number, which consequently disrupts the data flow.

tME nodes perform better due to their ability to make subjective decisions as mentioned in Section 4.2.


The subdivision algorithm must take into account the node density distribution (over the network map) and the sensors traf.c topology in order to equilibrate the failures density of the obtained subareas.

a-DPMS uses a partition mechanism called the Center Growth Algorithm presented in[10] initially designed to control the airtra.c.


Otherwise, bundles are temporarily stored and wait to be transmitted.

iBR-DTN assigns higher priority to incoming bundles, rather than to the ones already stored to be queued for transmission.


NetCore allows policy writers to match packets with arbitrary predicates; when predicates are not realizable on switches, packets are sent to the NetCore controller, which uses reactive specialization to install exact-match rules.

hFT s matching rules are simpler and realizable on OpenFlow switches, though we do not anticipate any problem supporting reactive specialization.


An important di.erence between the observed and GT-ITM latencies is that a 11We acknowledge that this approximation su.ers if the latency distribution varies substantially and qualitatively from point-to-point.

the approximation need only be good enough to capture the relative merits of di.erent approaches, and is not intended to provide quantitatively accurate descriptions of a method s performance.


Since FAST TCP utilizes queuing delay as a congestion signal, it can adjust its window size without inducing any packet loss when a new TCP connection joins the network.

fAST TCP cannot achieve fairness among existing connections and a new connection.


Once vehicle 1 passes vehicle 2, vehicle 2 should become the new message head.

vehicle 2 does not know this unless it receives an explicit notification from vehicle 1.


This seems to imply a nice PP invariant: ai = ci.

this is hard to maintain when clients have more dynamic behavior instead of being able to use the full available resources all the time.


DCTCP can achieve the highest goodput for inner-rack .ows.

its goodput drops signi.cantly for the other two categories of .ows.


Only one of those blocks was in the dataset, and that block is too sparse (only 4 active addresses) to apply Trinocular.

trinocular s lightweight probing means that it could have covered the whole analyzable Internet.


In such periods, a node may not overhear packets, and hence not update its GTS timer.

since a node in low-power state is not contending for the channel, collision avoidance is not crucial in this case.


On one hand, AEGIS allocates channels more ef.ciently among more buyers, hence the social welfare and revenue increase.

larger number of buyers leads to more intense competition on limited channels, thus decreases the satisfaction ratio.


Their results showed the upper bound for the delay between involved entities, under which LLH can support real-time services.

they consider these delays as constant parameters.


Network services are accordingly described and categorized in a highly-structured and information-rich fashion in an attempt to facilitate service matching.

this leads to increased memory footprints for service descriptions, becoming a problem in MANETs comprised by thin devices with memory limitations.


As soon as the source node receives the RERR, the route discovery will start.

if the failure happens nearby the destination node, the local repair will be activated.


In a separate question, 61.4% agreed or strongly agreed that they actually use a cell phone to support their job responsibilities.

34.6% of these staff members reported having a GGC-provided device.


Once the channel becomes idle, N1 begins the backoff operation.

instead of counting down from r1 th to 0, N1 transmits a symbol on the r1 subcarrier1.


The roles are installation of new E-UTRAN NodeB (eNB), Automatic Neighbor Relation (ANR), and automatic configuration on cell identities.

the latter one is related to measurements of User Equipment (UE) and eNB to tune the network automatically.


Certainly, this person or group and the system they use can be 1We typically have around 75% coverage for the darknet /8 in terms of effective unique /24 that are advertised and can receive traf.c.

the size of the darknet varies over time due to routing changes and suballocations.


The interference power of cell B s BS9 to the sensor is then given as Pcell B s BS · (3Rcell)-a = 1023.5 · (3 · 33 × 103)-3 W = -96.5 dBm, which is comparable to the noise power of -95.2 dBm in the 6 MHz band [19].

in (b), two cells that are three hops apart result in the interference power of -103 dBm, which is negligible.


For instance, two of these alarms occur after Time [s] Time [s] approximately 200 and 300 seconds, respectively; both can be interpreted as false alarms, since there is no obvious need for adjusting the system-state estimate.

the compensation (26) due to these events is not even noticeable for the first alarm, but causes a minor available-bandwidth overestimation for the second case.


if progress (measured as reception rate of data) is above some threshold 0 < a < 1, Deluge allows the node to continue making requests.


However, these policies do not distinguish types of requests, and capabilities and specialties of servers.

client-Aware Policy (CAP) [5] classifies requests into different types and tries to dispatch requests of each type to all servers evenly.


If node j belongs to every tree in J, then F().j =Yr/ j, and to have a feasible solution it is necessary that j resource rj be at least Y.


In addition, theworst case latencyinPaceline withfailover enabled is more predictable and consistent with a maximum con.dence interval of 1.

the worst case latency without failover varies considerably in congested networks with con.dence intervals reaching 10.


False positives for this rule occur when channel interference causes the message to distort.

due to link layer error checking, these false positives should be negligibly low.


Discriminating prefixes get surprisingly low: one Ri address has a discriminating prefix of 6 (since 7r6 > 0), meaning that some active 6-aggregate contains exactly one active address.

(the major- ity of addresses have discriminating prefix 26 or higher.)


Using a =2for radio rate(W) and a =0.5 for source packets-per-second(.d)and routing overhead pps(.l)), we have the CIVs as: 4 CIV(W)= 2.965; CIV(.d)= 2.811; CIV(.l)= 1.020 Thus, radio rate W and source rate .dare about equally dominant, providing approximately a 3x increase in scalability.

source rate is more easily changed by using a better codec for very little tradeoff in clarity.


A DAT transmitted by a node in the transfer mode is the same as that in ASAP.

an INF additionally contains the information on the frame length of the sender s neighbors as the information maintained by each node.


Finally, passive monitoring [30] is the most ef.cient and accurate since it uses actual data traf.c.

it also incurs the overhead of probing idle links.


The anchors are assumed to be distributed uniformly at randomin[0,1]d aswell.

itis reasonable to assume that we have some control over the positions of these special sensors, or the anchors, and in the following we show that we get similar performance bound with the minimum number of anchors(m = d+1) if the positions of the anchors are chosen properly.


), and drops to about 0.55 in the cluster with 15 nodes.

when saturation occurs in the cluster with 25 nodes, the success probability virtually drops to zero, as shown in Fig.


The number of alive nodes ( Nodealive ) in the networks decrease and the number of dead nodes ( Nodedead ) increase and then the accuracy of density is weakened.

like the traditional clustering method, the number of alive nodes decreases rapidly from the point of time when that number pass over a certain threshold after dead node's occurrence over time, and then the network lifetime terminates.


System 2 is obviously better than System 3, because it splits the tasks between suitable services equally.

the mainly reason leading to the failure of the QoS is that all the tasks are rushing to one server.


If the user is in a high-density sub-region, e.g., at a bus stop with many people waiting for buses, we may need a very large k in order to obtain a suitably large privacy region.

if the density is low, even a small k can bring about a very large cloaking region, which may then result in a very large intermediate query result.


The goal is for senders (e.g., S) to select the less resource constrained paths (e.g., S-X-Y-Z-D).

because redistributed routes are assigned a static metric values (e.g., at B, Y, A and X), the initial weight information is lost and senders may still select the congested paths (e.g., S-A-B-C-D).


Researchers in IEEE 802.16e task group (TGe) have proposed some mechanisms for security roaming of key association for fast handover in the new standard.

their schemes only support forward secrecy for the serving BS (SBS), without backward secrecy for the target BS (TBS).


The MOS metric has frequently been applied to investigate defects in audio quality introduced by distortion resulting from A-D or D-A conversion, quantization, and lossy compression schemes.

we are not aware of previous work that assigns Mean Opinion Scores to reliable playback of audio with interruptions.


McMAC assumes all nodes be able to transform their local clocks to that of their onehop neighbors, but they do not have to hop at the same boundaries.

no details are given as how to achieve so.


Thus, IC queueing delay is a good measure to compare the different arbitration rules used in different algorithms.

the transmission delay of a packet is equal to the sum of its IC queueing delay and its output queueing delay.


To make matters worse, in S-MAC the activity of all sensors inside a contention neighborhood is not distributed over time.

there are periods of inactivity and periods of contention.


Thus, the proactive algorithms pro- vide the routing information instantly when a mobile host needs to send data packets.

the flip side [or such protocols is that the excessive routing overhead transmitted is periodic in nature and lacks consideration for the net-work's mobility.


Thereby,beacons from farther distances maybe received.

it ispossible to achieve similar Low density High density D-FPAV full overhead 22.8% 41.4% D-FPAV reduced overhead 16.2% 18.6% DVDE/SPAV 0.42 % 0.42 %  Table 2: Overhead related to abeaconing of 10beacon messages per second, each with a size of 500 bytes.


7.2 Pathological Traf.c Pattern Replacing a core switch with a Quartz ring signi.cantly reduces latency and, for smaller networks with plans for growth, avoids the upfront cost of purchasing a large, expensive, and mostly empty core switch chassis.

a Quartz ring does not provide full bisection bandwidth, which can impact performance for certain workloads.


The contract negotiation is initiated by one of the parties.

depending on the steps followed in the negotiation, the recipient role could become the sender if the recipient accepts the contract proposal.


Thevast majority ofthesealertshavelowpriority and usually correspond to policy violations that are not directly related to security incidents.

a signi.cant portion, approximately 6%, consists of high priority alerts.


As expected, the RTT for both the routing schemes increases with the increase of the delay between the home network and the Internet.

due to its asymmetry, triangular routing RTTs are always lower with respect to reverse tunneling.


Thus, they share the same public/private key pair.

special nodes, called Super DLS (SDLS) are elected in order to act as authentication servers and are responsible for security establishment within a limited cluster of nodes (see figure 1).


The observation from the figures is that the reassignment algorithm reduces power consumed by an NDNx network, especially at light loads.

we note that estimations with the algorithm are the minimum values which would be obtained in ideal conditions.


In [1], ef.cient utility functions are developed for content dissemination, and [11] investigates optimal rate allocation schemes to maximize the data dissemination speed.

the content dissemination processes are not oriented for speci.ed destinations as in our work.


Therefore, the aggregation of whole tra.c in one time series produces a lot of false alarms for these heavy deviations.

the injected SYN .ooding attacksproduce small variationsinthe number ofSYN(lower thanexisting normal variations) asshowninFig.7.


Observe that pFabric achieves smaller FCT for up to 50% load and PASE achieves comparable performance.

at =60% loads, PASE results in smaller FCT than pFabric.


The transmitter can do so because it knows the channel to these receivers and hence it knows the attenuation its signal would experience.

if the resulting signalpower after channel attenuationisbelow L dB, thetransmitter contendsfortransmitting concurrently.if the signal power after channel attenuation is still higher than L, the transmitter reduces its own transmission power so that after attenuationitisless than L dB.The transmitter contends(and if it wins the contention transmits) at this lower power, which can be canceled usingpracticalinterference nulling and/or alignment.


In addition, the results in [20] and [32] are speci.c to the interactions between BGP and an IGP.

recent empirical studies [28], [25] show that operational networks frequently deploymultiple instances of IGP and join them through route redistributions rather than with BGP to achieveimportant design objectives such as ef.cient routing.


MadWi.supportsthestaggeredtransmission ofbeaconsfor each virtual AP, which is required for NAPman.

this feature requires hardware support to work.


We note that the running time increases with the increase of the number of sellers for both MWM and ORA.

for MM, the running time increases .rst and then becomes stable after m = n. This is because the maximum number of matching is limited by n even when m keeps increasing.


With a threshold of 10%, there are a total of six heavy hitters as notated in double circles.

reporting all heavy hitter pre.xes can be redundant; for example, reporting 01* as a heavy hitter is not as useful as reporting its descendent 010 which contributes the most to the traf.c volume.


Virtual time scheduling algorithms can be viewed as basing the relative priority of each client on the di.erence between the global real time anditspersonal virtual time, which re.ects an accounting of its consumption.

given that all clients share the same real time, it is enough to compare their consumptions and select the lowest one.


Selective Acknowledgments: The pTCP design does not impose any requirements on the design of the TCP-v protocol used by the individual pipes.

the use of TCP-SACK helps the performance of pTCP under certain conditions.


For example, as the beacon is being .ooded through the tendril, each node could append the received signal strength.

the nodes could append whether the node is a fully mobile node (e.g., mobile VoIP hand-set), or semipermanent (e.g., a desktop or consumer owned device that is speci.cally designed to act as a relay).


As our experiments presented in Section 7.5, AEDP is more energy e.cient at low data rates than the stateof-the-art receiver-initiated MAC protocol A-MAC [12], as AEDP avoids the overhead of the probe packets.

a-MAC is more energy e.cient than AEDP for high data rate applications, where the cost of sending these probe packets are o.set by reduced overhead for transmissions.


The scenario with one node redeployed is such a case, where the redeployed node only has .ve neighbors, resulting a detection rate of zero.

our scheme is highly effective in dense sensor networks such as in the 10x10 topology.


From this .gure we can see that at a given location, picking the wrong interface may provide very bad end-user experience.

mAR can easily provide a throughput that is much better than the best throughput provided by any interface.


Over the past few years, there has been a plethora of new massive-MIMO techniques proposed, such as [2, 3, 4, 5], and many more.

to date, most research regarding massive-MIMO has been restricted to theory that is based on analytical or simulation results.


5.4 Evaluating avoidance of false positives In §5.3, we show that our base algorithm has good accuracy on emulated blockages.

application of our basic algorithm to readings of our second sensor-pair (T 2 d and T 3 around the choke in Figure 2(a); downstream of the d sensor-pair Tu and T 1 around the valve) shows a number of d false alarms, even though there were no blockages at that location.


The small Fixed FEC adds a low overhead to the MPEG stream and works well with a low packet loss rate, but at higher loss rates, the playable frame rate decreases dramatically since the small Fixed FEC cannot provide enough protection.

the large Fixed FEC gives adequate protection in the presence of high loss rates, but also introduces a large amount of unnecessary overhead when the loss rates are low.


There is no exception for camera sensor networks, which combine the technology advancement in both computer vision and wireless sensor networks, and are believed to be the key component for many appealing applications.

because of the unique feature of camera sensors, the barrier coverage problem is more challenging and hence deserves more studies.


Given the almost universal use of TCP as the transport layer protocol in the current Internet, such works are clearly warranted.

several applications of ad-hoc networking, including more promising ones such as military battle.elds, disaster relief operations, etc., are environments where a completely revamped protocol stack tailored to the operating conditions is not merely feasible, but also justi.able.


In general, the num- ber of external LSAs depend on which prefixes are dynam- ically injected into OSPF domain.

one can use heuristics to determine external LSAs using the filtering clauses in configuration files that control external route in- jection.


campus-scale, city-scale or Internet-scale) networks.

other types of testbeds like [10,11,17, 22] can be built in small spaces such as laboratory rooms and thus can easily be used to test end system applications.


These algorithms maintain the slotted TDMA MAC protocol assumption of the original algorithm, but have not yet been translated to real implementations.

recent work applies backpressure ideas to build practical systems on top of existing MAC protocols, such as 802.11.


Pseudo Bayesian ALOHA (PB-ALHOA) [15] is an example on the additive class.

the additive methods can not properly track the network status in the case of high tra.c load [20].


In fact, the GPS modem is not strictly necessary, since location may rely on cell core-network location.

the power consumption and the size of the bracelets are relatively high.


The proposed algorithm can handle it well.

since this is not the focus of this paper, we do not present those similar results here.


Anumber of network abstractionshave been proposed in other contexts and could potentially be o.ered to tenants.

they su.er from several drawbacksdue totheirdense connectivity,andhence signi.cantly limit the true .exibility a multi-tenant datacenter can provide.


In contrast to raw network data, NetFlow data is widely available.

netFlow data imposes several challenges for performing accurate botnet detection.


More recent works recognized that di.erent driving contexts may warrant preferential allocation of resources to nodes in more potential danger.

existing methods allow users to relate the driving context to a corresponding share of the network resource, rather than a certain quality of service (QoS) level.


Meanwhile, ISPs formed a hierarchical structure and were classi.ed by tiers, with higher tier ISPs cover larger geographic regions and provide transit service for smaller/lower tier ISPs.

recent study [17] has reported that large content providers, e.g., Google and Microsoft, are deploying their own wide-area networks so as to bring content closer to users and bypassing Tier-1 ISPs on many paths.


By broadening the GeoRegion portion of the mapping, we weaken the state information: the uncertainty in the location of a node that is an element of the SetofIDs portion of the mapping increases every time the GeoRegion is expanded.

a mapping with a very large uncertainty level is not useful for making forwarding decisions.


The work in [4] investigates the problem of rule order optimization for packet .lters, and presents the outline of a greedy approximation algorithm.

the algorithm produces close to optimal solution only in the case when the ma jority of the rules are disjoint.


Inthe previous cases,the constraints comefromdirectmeasurements.

in networktomographytheconstraintsaregivenby(1).itis commontohave some combination ofthese sets of measurements.


Consequently, high output throughput values in this case do not correspond to increased delays through the router.

if the value of t is too large, it may have no relevance to the time scale at which queues are building up inside the router.


Rendering -period between the download completion and display of the .rst page of the document.

document retrieval over attestation-enhanced TLS can be broken down into stages: Request -period between the user s click on a link and the Web browser s display of the respective usage policies.


When node failures occur in the current shortest path, the second path can be chosen.

in an emergency situation such as a fire condition, many nodes can failure, including nodes from pre-defined and stored paths.


Our attraction to capabilities is that they cut to the heart of the DoS problem by allowing destinations to control the packets they receive.

capabilities are currently little understood at a detailed level or leave many important questions unanswered.


Learning from the previous literatures, the fixed-width clustering, KNN score and one-class SVM are proposed by authors in [7] were demonstrated that they are superior to those the above traditional anomaly detection techniques, especially the performance of one-class SVM algorithm both in detection true positive rate (TP) and false positive rate (FP).

their TP and FP are not as good as we expected (98% for TP and 10% for FP [7]).


Instead, we estimate the shuf.e completion time under the worst-case assumption: the background traf.c (i.e., the traf.c of .ow, regardless of the number of mice .ows generated by X.For 20 or more new VMs contacted by X, there is an impact on the throughput of X s long .ow.

we note that even if a VM were to contact so many new VMs per second with short .ows, it cannot sustain this rate for too long, since it would end up com municating with thousands of VMs in a short time.


100 80 60 40 20 0 10 20 30 40 50 60 70 80 90 100110120 Density Tput% vs Density for various Gain; 40 nodes; NumAnt=1 Figure3:Throughput:Steeredbeams,CSMA,nopower ontrol Thus,evenwithoneofthesimplestMACprotoolanda typialadhonetworkingalgorithm,therearesomegains inperformane.theyareprobablynotenoughto justifydeployingbeamformingantennas,andhenemotivate theenhanementsonsideredbelow.


In network management, NetDB [13] is probably the closest work to our vision.

it provides a read-only database abstraction for router con.gurations, where one can write queries to audit and analyze existing con.gurations in of.ine fashion.


Many works have focused on .nding energy-e.cient routing for maximizing the network lifetime.

they assume that all participants will follow the rules of the protocol.


This is made possible by each mobile host using a unique code that determines which slots a mobile host will use.

one limitation of these two topology-transparent approaches is that the maximum number of neighbours of any mobile host is known and bounded.


TWSS is an o.ering from IBM that enables Telecom operators to provide developers with controlled, reliable access to network capabilities such as Location, SMS and Call Control through standardsbased Parlay-X Web Services.

wPS is an application that collects, manages, and distributes realtime presence information to applications and users based on the SIP protocol.


Less restrictive forms of reverse path .ltering, loose uRPF [5], allow partial .ltering in some cases of asymmetry, but at the cost of unacceptably increased false negatives [39].

if anti-spoo.ng mechanisms are deployed at the edge of the network, the edge contains the largest number of devices and interfaces.


The .rst two commands are issued periodically, throttle with a median interdeparture time of about 2s and rtt-test with a median inter-departure time of about 11s.

log, SWITCH UP and BUFFER FAILURE are commands triggered on the occurrence of a particular event.


Some approaches, such as EPC Gen 2, use amplitude of the signal for edge detection.

those approaches lose phase information and lead to reduced SNR as well as potential errors in detection.


INTRODUCTION Wireless sensor networks (WSN) have fostered new models of collecting and broadcasting information with great potential use in the areas of environmental monitoring and intelligent buildings, to name a few.

a major hurdle in deploying a WSN is the limited battery life of a sensor node, requiring every node of a WSN to control its transmission power in such a way to maximize connectivity with lower power consumption.


In various ratios of sensing and communication range, the transmission latency remains small.

although all time interval of GAF can transmit packet, the random message transmission operation to compete as an active node will lead to transmission latency due to packet collision and retransmission.


Theminimum and maximumtransmitpower values can be di.erent on di.erent 802.11 cards, vary with the frequencies used (such as in the 5GHz band) and also vary based on the gains of the external antennas connected to the cards.

we assume that the levels are discreteatagranularity of3dB.In ourprototypewithAtheros cards, we vary the power levels between 0 and 18 dBm.


One approach is to .nd a routing scheme that minimizes the total power consumed by all nodes, e.g., [23], [3], [19], [25].

such an approach does not guarantee that the network lifetime is maximized.


Sometimes, the error is only incidental and the experiment completes successfully on the next attempt.

it could be due to a design  Figure 5: AES Error Reporting error in the experiment, a con.guration error in the virtual machine, something speci.c about the object of the experiment (a particular malware sample or exploit), an error in the host (con.guration error in VMware), etc.


could assign specific bits or combinations of bits 2 to have predeter- mined meanings.

at this point, we are not certain about the general usefulness of such a feature.


Because of the large variety of computations matching information can involve, we choose not to formalize the construction of a pattern besides specifying its inputs and outputs.

coull s adversarial model [3] may make a good model for a pattern in many cases of .ngerprinting or structure recognition attacks.


Thus if multiple repetitions of the computation produce the same result it is very likely to be correct.

the two-phase aggregation service described in Section 3.2 will fail silently or produce an incorrect result if even one message is lost.


These results indicate that, as shown in [17], the FastTrack network is highly polluted.

good copies are easy to .nd among the mostly replicated objects.


Diversity in DNS Performance Measures Richard Liston, Sridhar Snnivasan, Ellen Zegura Abstractm DNS is a critical component of the operation of Internet applications.

dNS performance in the wide-area is not well understood.


and path length D) have negligible in.uence on the detection rates.

the detection rate of PAAI-2 heavily depends on the path length D. 1 For example, if we set s =0.03 and p = d2 , and choose an arbitrary network setting where a =0.03, .


Under this constraint, the unlisted properties among (P.1)  (P.5) can be proved for the combination of t.a.c or v.b.c stochastic arrival curve and weak stochastic service curve.

the formulation usually is much more complex (e.g.


Thus, LEACH achieves energy e.ciency by reducing the total number of data messages to be transmitted and by the introduction of a small number of dedicated CH nodes for data collection, fusion, and transmission.

lEACH does not take into account of the distance and the residual energy of the nodes to be elected as CH node.


Recent studies show that, in mobile ad hoc networks (MANETs and VANETs), the proactive routing protocols, generally, outperform the reactive ones in terms of network goodput and end-to-end delay [10, 26].

proactive protocols su.er from a higher routing overhead, limiting their performance in terms of energy-e.ciency [3].


Quality of Service is mainly related to resource allocation and management, where it is necessary to decide how to allocate resources such that QoS requirements of all flows can be satisfied as best as possible.


The IDIPS related work in such a context is P4P, Oracle and ALTO [8, 2, 7].

unlike these related works, IDIPS is not limited to the peers selection in P2P and can measure path performances.


Even with one more metric, the second combination can achieve the true positive rate of 94.44% for the controlled environment trace and only 59.43% for the normal-tra.c trace.

in terms of transferred bytes, these identi.ed hosts still constitute a signi.cant share of the total bittorrent tra.c, especially in the controlled trace (98.76% oftracetotal tra.c).


Uplink Protection It may be possible to protect a server from DoS attacks by constraining direct connectivity to the server, using, for instance, a Virtual Private Network (VPN).

even if the server is not directly vulnerable, DoS can still occur if the Internet uplink of the server is .ooded.


Theoretically, using a 40 MHz band should double the amount of throughput achieved using a 20 MHz band.

as shown in Figure 1, all the 40 MHz channels are partially overlapping in the 2.4 GHz band, as opposed to the 20 MHz channels 1, 6 and 11 which are non-overlapping.


This is because more paths with shorter end-toend delay are found with the increase of node density.

in the high node density region, the delay of MPT increases slightly.


It is seeking to estimate the next pulse ci c1 receive time in terms of ci Thus, E( ym+1)= t = ai(s ll - n,i n,1 c1 c1 c1 .¯i)+mai.

in terms of c1, E( y )=t=s ll + m+1n,i n,1 c1 m. Also, since the variance s2 is de.ned in terms of ci,Var( ym+1) will also have a different value since we do a linear transformation to get from y c1 we will not go through the ym+1 to m+1.


As mentioned, UDP is message-based and one can avoid all the heavy-weight mechanisms present in TCP to obtain better performance.

when ones adds reliability on top of UDP the advantages begin to diminish.


Theresulting softwarecanbeused asavalidationplatformforseveralsharingpolicies,possiblyderived withinagame theoreticanalysis.Inthefollowing,we willshowsampleresultsfor orthogonal competitive sharing.

given the modular natureofthesimulator,morecomplex gametheoretic approaches can be framed, even resorting to dynamic games, Stackelberg games andso on[17,21].


Energy consumption for different number of sink nodes Figure 10 indicates that CBDD's energy saving was about two times greater than that of TTDD when there were 2 sink nodes.

the difference abated as the number of sink nodes increased.


],explicit feedbackformoreadeptcongestion control[..],and other novelfeatures.


The EDEN technique measures the time spent on a client (or an AP) by measuring the times of the Snoop request and response packets at nearby clients.

this measurement includes the delay at the machine due to medium contention.


1, as one can de.ne the coe.cients using (j) * ai = hi(s ,f,j),i =1,...,m -1, where j corresponds to the jthpolynomial, and hi is a suitable pseudorandom function.

the communication cost is a linear function of W , and thus the scheme becomes too tedious when W is large.


Errors and discontinuities in the pipe estimator can cause signi.cant errors in the amount of data sent.

pRR regulates the transmission rate based on the actual amount of data delivered at the receiver, DeliveredData.


The implementation and decision basis to change the rate are usually proprietary though some general heuristics are known [12].

the implicit assumption is that lowering the rate will decrease the probability of packet error.


We .nd that the most signi.cant sources of throughput variability are the access technology, ISPs traf.c shaping policies, and congestion during peak hours.

latency is mostly affected by the quality of the access link, modem buffering, and cross-traf.c within the home.


Unlike broadcast packets, unicast packets in 802.11 are retransmitted up to 4 times by the MAC layer and have a higher probability of arriving at their destination.

if MAC layer retransmissions arrive, they have a larger latency than packets that were not lost.


[11] presents an analysis based on Network Calculus to exploit the correlation of tra.c streams due to the serialization on AFDX s virtual links.

this analysis is limited to strictly periodic tra.c streams, which reduces the combinatorial complexity of .nding an upper bound on the workload induced by a set of correlated streams.


Figure6(a):SessionfailurewhenMNN1-HQ  Figure6(b):SessionfailurewhenHQ-MNN1  ThereisnocalldropinSMONforallmovingpatterns.On theotherhand,inMANEMO-AandMANEMO-Bwecan seefromFigures6(a)and(b)that most ofthecallsare droppedduringattachment.Thenumberothemovementcall dropsishasnodeschangeitheirpoints  offgherwhilethe call ismade fromanMNN totheHQincaseof MANEMO-A,asshowninFigure6(a),becauseduringa  handoverthereisnoroutetotheHQ.Hence,allcallsmade s timeare mmediateydroppedwithouS duringthNVIiries.While,thenumberoilfcall failures(t IP ITEretHQto MNN)islessthanthatofMNNtoHQbecausetheHQstill doesnot receiveaBindingUpdatefromtheMRduringthe  movements.Therefore,it usesthepreviouscare-of-address tocommunicatewith theMR.

all SIPINVITErequests  aredroppedduring thishandover.once the handoverisfinished,SIPINVITErequestscanreachthe    Figure7(a):AveragesessionsetupdelaywhenMNN1-HQ  Figure7(b):AveragesessionsetupdelaywhenHQ-MNN1 Figures7(a)and(b)showthecomparisonoftheaverage  sessionsetuptimeamongthethreesystems.Wehavemade 200calls for each system for each type ofmovement pattern.Thedropcallsareconsideredasthedurationof32 sec(IETFRFC3261).ItisobservedfromFigures7(a)and (b)that thesessionsetuptime forSMONissteadyinthe wholeperiodofexperiment.Theaveragetimeforsession setupismuchhigherinMANEMO-Aduetocall dropand longerhandovertime.


This is because UA su.ers from queue over.ow, which results in sending fewer packets for a given .le size.

for NA, we multiply the total number of transmissions by two because we do not have the NA results for the star topology.


In recent years, there has been an increasing understanding on the algorithm design that target various aspects of QoS, especially packet delivery ratio requirement (e.g., [5], [6], [7]).

there has been considerably less progress associated with the regularity of service, which is clearly a scales no faster than the order of v1c , where E measures 5 the closeness of the network load to the boundary of the capacity region.


Two Bluetooth devices must be initially paired with each other to perform an OBEX transfer (see Section 3.2).

blue-Monarch uses SDP to emulate transfers and thus the probing device need not be paired with the receiver to perform its emulated transfer.


Figure 2.a shows that the bandwidth consumption of (N2) for small group sizes is below (A1)'s requirements.

for large group sizes and higher loss probability, (N2)'s bandwidth consumption is 2,5 times the bzmdwidth consumption of (A1).


In a multi-AP WLAN, two nearby stations might not be eligible for concurrent transmission if they are restricted to transmit to their associated APs.

two nearby stations might be eligible for concurrent transmissions if their packets can be received by any AP.


Google News .nished loading in 3.81 s (725%), Yahoo in 11.11 s (778%), WSJ in 14.40 s (447%) and CNN in 20.18 s (570%) for FIFO.

cHAP managed to keep the Web response time low and close to the Web response time in the absence of the bulk .le download.


In fact, the system tries to pro.t from the available resources in order to provide the best possible accuracy.

the use of a small time scale (t = 600s) leads to an oscillating behavior of the overhead since the system tracks more details and changes in the traf.c while tracking changes on a large scale(t = 5400s)leads to a stable behavior of the overhead.


This forwarding method is effectively epidemic in our emergency scenario, since all nodes have interest in delivering this information to the coordination point.

sending data in an epidemic way in emergency scenarios may not be e.cient.


Now we discuss how to choose parameter d. Since the purpose of scan is to find potential AP to get connected, it s reasonable that if the mobile phone user does not move, then the probability to find new AP by scan is rather small.

people are subject to move around in short distance compared with AP s coverage range, especially at home or office, so we should take both the moving distance and AP s coverage distance together into consideration.


For example, it is typically assumed that we are given the probabilities and utilities in an MDP, and that we must then construct an opt~m~_l admission policy.

in a wireless network, the probabilities are themselves influenced by the admission policy we construct.


Indeed, existing QR codes often encode a single URL, and require cellular or WiFi connectivity for access to additional information.

public displays are also widely available, and, when combined with smartphone cameras, form communication links that can complement RF wireless connectivity, as suggested in previous works[10, 15].


The aggregate throughput increases from 17.9 Mbps to18.6 Mbps.

cENTAUR with10 msepochs cantake advantage ofsome exposedterminals andincreasetheirthroughput evenfurther(e.g.,link8)by 1.8×.Onthe whole, CENTAUR with 10 ms epochsimproves aggregate throughput across alllinks46% overDCF.


INTRODUCTION Multimedia underwater sensor networks [1] would enable new applications for underwater multimedia surveillance, undersea explorations, video-assisted navigation and environmental monitoring.

these applications require much higher data rates 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 pro.t or commercial advantage and that copies bear this notice and the full citation on the .rst page.


It is not an issue for APs in traditional scenarios because they are exter-nally powered.

such old design wisdom does not work for the battery-powered SoftAPs in Wi-Fi tethering.


An alternative approach, called Time Division Multiple Access (TDMA), that solves both the hidden transmitter problem and the idle channel detection delay problem is to assign unique data packet time slots to each transmitter in a channel contention region (the area within which simultaneous transmission from two transmitters can interfere at a common receiver).

adoption of TDMA protocols in wireless sensor networks has been slow for many reasons, as pointed out by the authors of S-MAC [4].


Since protocol-driven methods piggyback CSA information to protocol messages, they deliver address information where it is needed.

gossip dissemination does not speci.cally direct address lists to nodes affected by the departure event.


In this simulation, when the number of servers is small, the maximum expected latency is close to the mean of 100 µs (the 50th percentile of the random variable).

as S grows the maximum observed value approaches the 99th percentile value of 254.25µs.


Our emulation shows that selecting the proper network for single-path TCP can reduce response time by 50% compared to the minimum of the single-path TCP throughputs on LTE and WiFi.

using MPTCP reduces application response time by only 35%.


The answer to this question lies in the speci.c channel characteristics experienced by the mobile device.

at the same time, the staggered delay should not exceed the round-trip time of the connection, as otherwise the mechanism would lose its signi.cance.


Both algorithms can be uploaded to the same node for broadcast and unicast channel computation.

broadcast may be inferior to unicast, as in IEEE 802.11 standard.


Overall, we see that burst mode transfer with coordination is still a little lower (7.7%) in total goodput than the uncoordinated case.

the un-coordinated case gives out more than 87.3% of the channel to one of the three tags.


4.1 Performance Evaluation To properly evaluate the accuracy of the algorithms, we need to measure the RTTs to the destinations in a group and the ingress routers of a randomly selected pre.x in the group simultaneously because route changes can cause some errors in RTT measurements.

the data set has been collected over a long period, so it does not provide such information.


For a fully active CSMA-based MAC, time on is always now and time off is always never.

for a TDMAbased MAC, the values correspond to the next time slot and its duration.


Unfortunately snooping, like any caching scheme works on the assumption that information gathered in the past can be used for some period of time in the future.

when users in the network are very mobile, one of two things may happen: 1) entries become stale (large lifetime values), thus packet loss may occur or 2) entries expire early (short lifetime values), resulting in a large of amount of data broadcasts.


Recently, .ber optic links have become increasingly popular for cluster interconnects because they can achieve higher data rates and lower bit-error rates over long cables than low-voltage di.erential signaling over copper wire.

optical links require a transceiver that converts from optical to electrical signals so the silicon circuits can perform their switching decisions.


INTRODUCTION Underwater acoustic networks havereceived rapidly growing research interests in the last few years since they can bring about signi.cant bene.ts in a wide range of aquatic applications [1, 2, 3, 4, 5].

because of the unique characteristics of underwater acoustic channels such as limited available bandwidth, long propagation delays and extensive time-varying multi-path effects, and the harsh underwater environments,building autonomous underwater acoustic networks encounters great challenges at almost every layers of the protocol stack, among which ef.cient medium access control (MAC) is one of the most fundamental issues.


From the figures it is clear that the L2 mechanism is the most efficient solution with lower densities, but is the worst under higher densities.

the OLSR mechanism improves if density is increased due to the reduction of the number of hops needed to communicate distant nodes.


Therefore, inter-domain operations and signaling between networks should be considered in the Proxy Mobile IPv6 environment.

authentication procedure and policy profile retrieval procedure of a mobile node over layer-3 are performed by the visited AAA (policy store) server in the Proxy Mobile IPv6.


2.2.1 Finding the repeater and branching When a node is selected to forward a packet and it is outside the transmission range of a repeater, it continues with the directional broadcast protocol as described in Section 2.1.

if the node is inside the transmission range of a repeater, the node sends the packet to the repeater using the point-to-point IEEE 802.11 protocol.


Since UDP does not have congestion and .ow control mechanisms, its transmission resumes immediately after the PS service is available.

tCP RTO may not expire yet though the PS service resumes.


When there is traf.c congestion on the highway, it is possible that the minimum speed is small and satis.es va = r/c.

congestion may be local and occurs only in one or two lanes.


4.3 Delay-Driven routing The key requirement in delay-driven routing in serial Path- Finder is to compute the value of the longest path of the entire circuit, D,~, at each iteration [7].

in Parallel PathFinder, processor i only has a sub- set of the signals to route.


Using the truthful link loss probabilities, MORE will calculate that R s expected number of transmissions is 1.18.

by cheating MORE to use 0.1 as the loss probability on link (R,D), node Rcan reduce its expected number of transmissions to 0.78, a reduction of expected workload by 34%.