Survey of Media Access Control (MAC) and Routing Technologies of WiFi-MESH wireless Network <s> HWMP Routing Protocol and Its Improvement Technologies <s> Wireless Mesh Networks (WMNs) are broadly used recently, due to its flexibility, reliability and robust services. IEEE 802.11s defines Hybrid Wireless Mesh Protocol (HWMP) as the default routing protocol for WMNs and airtime link metric as the default path selection metric. Airtime metric can collect the channel information from both PHY and MAC layers to estimate average latency per packet transmission through a link, but it typically suffers from several shortcomings, such as ignoring the influence of traffic flow and inefficient usage of the shared wireless resources. In this paper, we propose a modified HWMP protocol with an enhanced airtime metric called as HWMP+, which can estimate the link quality in combination with traffic flow information and allocate the network resources in an efficient way. The proposed metric computation procedure has both historical and real-time perspectives of the link quality and is more sensitive to the link quality variations, especially in a dynamic topology. We also improve the routing scheme and optimally manage the shared channel resources according to the traffic flow information. Simulation results using Qualnet 5.0 show that, the proposed schemes can considerably improve the system performance, in terms of network throughput and average end-to-end delay. <s> BIB001 </s> Survey of Media Access Control (MAC) and Routing Technologies of WiFi-MESH wireless Network <s> HWMP Routing Protocol and Its Improvement Technologies <s> As a standard of Wireless Mesh Networks, IEEE 802.11s has been emerged as a new MAC protocol and confronted with a commercialization phase. IEEE 802.11s adopts two kinds of MAC protocol, CSMA-based EDCA and TDMA-based MCCA. MCCA is a method to reserve bandwidth within 2-hop neighbors, but it cannot reserve the end-to-end bandwidth. So, in this paper, we suggests a Reservation-based HWMP (R-HWMP) satisfying the end-to-end QoS. The proposed protocol attempts to find a path satisfying the requested QoS first, and reserves the resource using MCCA. Through NS-2 simulation, we show that the proposed protocol guarantees the end-to-end QoS and outperforms to legacy contention-based DCF. <s> BIB002 </s> Survey of Media Access Control (MAC) and Routing Technologies of WiFi-MESH wireless Network <s> HWMP Routing Protocol and Its Improvement Technologies <s> Integration of Vehicular Ad-hoc Network (VANET) and Universal Mobile Telecommunication System (UMTS) is a promising architecture for future machine-to-machine applications. This integration helps the vehicles have steady Internet connection through UMTS network and at the same time can communicate with other vehicles. However, the dead spot areas and unsuccessfully handoff processes due to the high speed of the vehicles can disrupt the implementation of this kind of architecture. In this paper, a new Simplified Gateway Selection (SGS) scheme for multihop relay in VANET-UMTS integration network is proposed. The main aim of this research is to enhance the integration between VANET and UMTS network, and extend the coverage in the area where there is no coverage, and reduce the amount of overhead, and reduce delay metrics, and increasing the packet delivery ratio, and also to reduce the dead spot in VANET-UMTS network. An enhanced version of HWMP is a combination of IEEE802.11p and IEEE802.11s for multihop vehicular communications is proposed. An integrated simulation environment combined of VanetMobiSim and NS2 is used to simulate and evaluate the proposed scheme. The simulations results show that, E-HWMP protocol performed better than Ad-hoc on demand Distance Vector (AODV) routing protocol. Furthermore, E-HWMP is compared with other cluster-based gateway selection that used in the previous works; the result shows that our E-HWMP protocol outperforms the other cluster based gateway selections schemes in terms of connection delay, control packet overhead, packet delivery ratio and overall throughput. <s> BIB003
HWMP protocol is a comprehensive protocol which is developed by 802.11s Task Group for WiFi-Mesh network. This protocol absorbs the advantages of both reactionary routing protocol and proactive routing protocol based on tree topology, which is more compatible with Wireless Mesh Network. The current improvement policies mainly optimize property of system through different routing metrics as follows: Reservation-based HWMP (R-HWMP) BIB002 protocol upgrade Quality of Service through introducing fields of RSpec and TSpec; HWMP-ETX  , Q-HWMP [17] and HWMP+ BIB001 protocols reduce the delay and packet loss probability through introducing Expected Transmission count, and delay, link quality, throughput and other routing metrics; Eltahir and other scholars BIB003 introduce a Link Expiration Time(LET for short) into routing metrics taking advantage of stability of LET decisive link, which can increase mobile adaptive ability. In addition, energy-efficient HWMP protocol  strengthen energy validity through making surplus energy of nodes as routing metrics. Improvement policies mentioned above can raise up QoS, time delay, throughput of information, energy validity and other properties to some extent. However, just as the traditional protocols, they are lacking in valid strategies of congestion control and don't fully consider load balancing, and the traffic overload of root nodes in networks would appear if there is a large amount of data waiting for transmission.