A Five-Phase Reservation Protocol (FPRP) for Mobile Ad Hoc Networks

A new single channel, TDMA-based broadcast scheduling protocol, termed the Five-Phase Reservation Protocol (FPRP), is presented for mobile ad hoc networks. The protocol jointly and simultaneously performs the tasks of channel access and node broadcast scheduling. The protocol allows nodes to make reservations within TDMA broadcast schedules. It employs a contention-based mechanism with which nodes compete with each other to acquire the TDMA slots. The FPRP is free of the ``hidden terminal" problem, and is designed such that reservations can be made quickly and efficiently with minimal probability of conflict. It is fully distributed and parallel (a reservation is made through a localized conversation between nodes in a 2-hop neighborhood), and is thus arbitrarily scalable. A ``multihop ALOHA" policy is developed to support the FPRP. This policy uses a multihop, pseudo-Baysian algorithm to calculate contention probabilities and enable faster convergence of the reservation procedure. The performance of the protocol is studied via simulation, and the node coloring process is seen to be as effective as an existing centralized approach. Some future work and applications are also discussed

A New Distributed Slot Assignment Algorithm for Wireless Sensor Network Under Convergecast Data Traffic

The scarcest resource for most of the wireless sensor networks (WSNs) is energy and one of the major factors in energy consumption for WSNs is due to communication. Not only transmission but also reception is the source of energy consumption. The lore to decrease energy consumption is to turn off radio circuit when it is not needed. This is why TDMA has advantages over contention based methods. Time slot assignment algorithm is an essential part of TDMA based systems. Although centralized time slot assignment protocols are preferred in many WSNs, centralized approach is not scalable. In this paper, a new energy efficient and delay sensitive distributed time slot assignment algorithm (DTSM) is proposed for sensor networks under convergecast traffic pattern. DTSM which is developed as part of the military monitory (MILMON) system introduced in [27], aims to operate with low delay and low energy. Instead of collision based periods, it assigns slots by the help of tiny request slots. While traditional slot assignment algorithms do not allow assigning the same slot within two hop neighbors, because of the hidden node problem, DTSM can assign, if assignment is suitable for convergecast traffic. Simulation results have shown that delay and energy consumption performance of DTSM is superior to FPRP, DRAND, and TRAMA which are the most known distributed slot assignment protocols for WSNs or ad hoc networks. Although DTSM has somewhat long execution time, its scalability characteristic may provide application specific time durations

An Evolutionary-TDMA Scheduling Protocol (E-TDMA) for Mobile Ad Hoc Networks

A new single channel, time division multiple access (TDMA) schedulingprotocol, termed "Evolutionary-TDMA", is presented for mobile ad hocnetworks. The protocol allows nodes in an ad hoc network to reserveconflict-free TDMA slots for transmission to their neighbors. Two topology-dependent schedules are generated and maintained simultaneously. One is a broadcast schedule inwhich every node has one slot to transmit to all its neighbors. The other isa flexible schedule in which a node can reserve multiple slotsfor transmission of unicast, multicast and broadcast traffic. The schedules are reasonably bandwidth efficient and are frequently updated in an evolutionary manner to maintain conflict-free transmissions. The protocol executes across the entire network simultaneously in a fully distributed and parallel fashion. To react quickly to changing topology and bandwidth demands and to keep overhead low,participating nodes need only coordinate with their one-hop neighbors.Traffic prioritization and Quality of Service (QoS) can be supported with this protocol. Its performance, in terms of both scheduling quality and scheduling overhead, is insensitive to network size. Thus,it is a scalable protocol suitable for very large networks, and networks of varying size

COMB: Cell based Orientation aware MANET Broadcast MAC layer

The design of a collision avoidance system for trains implies the design of a MAC layer for their specific requirements. It should be efficient, reliable, use broadcast and support wireless mobile ad hoc networks (MANETs) with high user speeds. Therefore we are using awareness techniques, which allow a certain channel assignment, despite the absence of infrastructure. This paper presents a new MAC layer protocol designed for broadcast MANETs called COMB (Cell-based Orientation-aware MANET Broadcast). In principle, COMB allows the realization of a collision free transmission, high speed is supported and no handshake is required. COMB is based on localization aware cross layer dimensioned CDMA cells, and uses the SOTDMA protocol as intra cell scheme, while the inter cell scheme relies on direction and speed awareness

An Evolutionary-TDMA Scheduling Protocol (E-TDMA) for Mobile Ad Hoc Networks

A new single channel, time division multiple access (TDMA)scheduling protocol, termed "Evolutionary-TDMA", is presented for mobilead hoc networks. The protocol allows nodes in an ad hoc network toreserve conflict-free TDMA slots for transmission to their neighbors.Two topology-dependent schedules are generated and maintained by theprotocol: a broadcast schedule suitable for network control traffic anda mixed schedule which combines unicast, multicast and broadcasttransmissions for user data traffic. The schedules are frequentlyupdated in an evolutionary manner to maintain conflict-freetransmissions. The protocol executes across the entire networksimultaneously in a fully-distributed and parallel fashion. Trafficprioritization and Quality of Service (QoS) can be supported.Simulations have shown that the performance of the E-TDMA protocol isclose to that of centralized algorithms, while being insensitive tonetwork size in terms of scheduling quality and scheduling overhead. Itis a scalable protocol suitable for very large networks, and networks ofvarying size

A dynamic distributed multi-channel TDMA slot management protocol for ad hoc networks

With the emergence of new technologies and standards for wireless communications and an increase in application and user requirements, the number and density of deployed wireless ad hoc networks is increasing. For deterministic ad hoc networks, Time-Division Multiple Access (TDMA) is a popular medium access scheme, with many distributed TDMA scheduling algorithms being proposed. However, with increasing traffic demands and the number of wireless devices, proposed protocols are facing scalability issues. Besides, these protocols are achieving suboptimal spatial spectrum reuse as a result of the unsolved exposed node problem. Due to a shortage of available spectrum, a shift from fixed spectrum allocation to more dynamic spectrum sharing is anticipated. For dynamic spectrum sharing, improved distributed scheduling protocols are needed to increase spectral efficiency and support the coexistence of multiple co-located networks. Hence, in this paper, we propose a dynamic distributed multi-channel TDMA (DDMC-TDMA) slot management protocol based on control messages exchanged between one-hop network neighbors and execution of slot allocation and removal procedures between sender and receiver nodes. DDMC-TDMA is a topology-agnostic slot management protocol suitable for large-scale and high-density ad hoc networks. The performance of DDMC-TDMA has been evaluated for various topologies and scenarios in the ns-3 simulator. Simulation results indicate that DDMC-TDMA offers near-optimal spectrum utilization by solving both hidden and exposed node problems. Moreover, it proves to be a highly scalable protocol, showing no performance degradation for large-scale and high-density networks and achieving coexistence with unknown wireless networks operating in the same wireless domain

Research On Routing Protocol and Channel Access Protocol in Wireless Ad hoc Networks

近年来，随着研究的深入和相关硬件技术的发展与成熟，无线自组网(WirelessAdhocNetworks)技术在实际应用中得到越来越多的部署。无线自组网是一种无中心、自组织的无线移动通信网络。无线自组网中没有中心访问节点或者固定的基础设施，各个节点通过分布式算法相互协调完成网络的通信功能。由于自组网节点能量有限，路由的选择很大程度上影响了节点的寿命。信道接入协议是无线自组网协议栈的重要组成部分，决定了节点如何通过共享的无线空间信道发送和接收数据包。信道接入协议能否高效的利用有限的无线信道资源对无线自组网的性能有决定性的影响。 本文正是在这样的时代背景下，针对无线自组网中的路由协议与信道接入协...In recent years, with the in-depth research of related technologies and the improvement in hardware, there are more and more deployed wireless ad hoc networks in practice. Wireless Ad hoc Network is a kind of self-organized communication network without center. There are no central nodes or fixed communication infrastructures in the network, in which all the nodes communicate with each other by di...学位：工学硕士院系专业：信息科学与技术学院计算机科学系_计算机软件与理论学号：2302007115125

A New Protocol for Scheduling TDMA Transmissions in Mobile Ad Hoc Networks

A new protocol for scheduling TDMA transmission in a mobile ad hoc network isdeveloped. With this protocol, nodes reserve time slots for unicast, multicastor broadcast transmission. The protocol uses contention for nodes to reservetransmission time slots, its operation is distributed and concurrent; thereforeit is independent of the network size and can be used in large or dynamicnetworks. Its performance is studied with simulation and compared with IEEE 802.11 protocol