This paper introduces a new IEEE standard, IEEE 802.15.5,which provides mesh capability for wireless personal area network (WPAN) devices. The standard provides an architectural framework enabling WPAN devices to promote interoperable, stable, and scalable wireless mesh topologies. It is composed of two parts: low-rate WPAN mesh and high-rate WPAN mesh. In this paper, we present only low-rate WPAN mesh because it is designed to support wireless sensor networks. IEEE 802.15.5 low-rate part is a light-weight scalable mesh routing protocol that caters well to the requirements of resource-constrained wireless sensor networks. By binding logical addresses to the network topology, IEEE 802.15.5 obviates the need for route discovery. This eliminates the initial route discovery latency, saves storage space and reduces the communication overhead and energy consumption. A distributed link state scheme is further built atop the block addressing scheme to improve the quality of routes, robustness, and load balancing. The routing scheme scales well with regard to various performance metrics. The standard also provides enhanced functions such as multicast, reliable broadcast, power saving, time synchronization, route tracing and portability. We also present the performance evaluation of major functions performed with a 50-nodes tested deployed over a whole floor (100 × 140 ft2) at CUNY Engineering building. The results testify that the IEEE 802.15.5 will serve well for wireless personal area networks and wireless sensor networks.

This article presents an in-depth introduction and analysis of the low-data-rate portion of the IEEE standard 802.15.5 that targets on providing mesh capabilities to low-rate wireless personal area networks. As major contributors of this standard, we seek to share our insights and motivations of the approaches adopted in the major components of the standard instead of presenting a la carte items drawn in the specification. We wish this article helps readers of the 802.15.5 standard to better understand the rationale and intent of the protocol design. This article also compares 802.15.5 to ZigBeetrade and 6LoWPAN, for users to select the best mesh network technology for their applications.

This paper presents a new medium access control (MAC) scheme, which exploits the code division multiple access (CDMA) technology to provision many-to-one simultaneous wireless communication service without utilizing any time division multiple access (TDMA) scheme. This, combined with existing one-to-one (i.e., unicast) and one-to-many (i.e., multicast or broadcast) wireless communication services, brings into life a new communication paradigm, that is, mesh communications. The new scheme also supports accumulative receptions, namely, a receiver can buffer partially damaged (re-)transmitted frames and add those frames efficiently to form an error-free frame. Our simulation results show that the new scheme outperforms IEEE 802.11 in both non-mobile and mobile environments.

Low rate wireless personal area networks (LR-WPANs) offer device level wireless connectivity. They bring to light a host of new applications as well as enhance existing applications. Due to their low cost, low power consumption and self-organization features, LR-WPANs are ideal for applications such as public security, battle field monitoring, inventory tracking, as well as home and office automation. Nevertheless, one critical issue, security, needs to be solved before LR-WPANs are commonly accepted. Pursuing security in LR-WPANs is a challenging task. On one hand, wireless communications are inherently susceptible to interception and interference. On the other hand, most devices in LR-WPANs are resource-constrained and lack physical safeguards. This paper presents a systematic analysis of the threats faced by LR-WPANs with respect to the protocol stack defined by IEEE 802.15.4 and the ZigBee Alliance. Attacks are modeled and their impacts are evaluated. Some security problems within the current LR-WPAN security architecture are identified and remedies are suggested. Countermeasures of various attacks are also given.

Reliable server pooling (RSP) allows a pool of redundant information sources to be viewed as a single transport endpoint and, therefore, it is able to provide persistent connections and balanced traffic for different applications. The Internet Engineering Task Force RSerPool Working Group has proposed an architecture to implement the RSP; it defines an overlay network providing an upper layer protocol or an application with a range of reliability services, from simple server selection to a fully automatic session-failover capability. The simulation experiments conducted in both wired and wireless environments show that the current version of the RSerPool works well in fixed and relatively reliable environments, but its performance worsens rapidly as the networks become more unreliable or mobile. The issues we have identified in wireless mobile ad hoc networks include network partition, high signaling overhead, difficulty in synchronization among name servers, and excessive aggressiveness in handling failures. Alternative design options for the RSP in wireless and mobile environments are introduced and evaluated.

The reliable server pooling is a framework to handle session failures and increase the system's availability by providing several reliability services: from simple server selection to a full session-failover capability. In the IETF RSerPool, servers with equivalent functionality are pooled together; when a particular server becomes unavailable, a client application can transparently switched over to another server in the pool. Extensive simulation experiments identified two main shortcomings of the RSerPool in wireless mobile networks: the inaccuracy of the failure-detection mechanism for pooled servers, and high overhead of finding name servers. We introduce and evaluate alternative mechanisms that tackle these problems.

The reliable server pooling allows redundant information sources to be viewed as a single transport endpoint, and therefore is able to provide persistent connections and balanced traffic. The IETF RSerPool Working Group has proposed an architecture to implement the reliable server pooling. We conducted a number of simulation experiments with the current definitions of the RSerPool protocols to quantify their performance in both wired and wireless environments. The simulation results show that the RSerPool works well in fixed and relatively reliable environments, but its performance worsens rapidly as the networks become more unreliable or mobile. The issues we identified in wireless mobile ad-hoc networks include network partitioning, high signaling overhead, and excessive aggressiveness in handling failures. These problems are partly due to the heavy reliance of the RSerPool architecture on the reliability of the underlying network,, which is unlikely to be guaranteed in a wireless mobile ad-hoc environment.