Frequency rolling

As the wireless personal area network (WPAN) gets utilized by more individuals, the interference that collocated WPANs cause to each other, termed self-interference, will be one of the major sources that degrade WPAN's communication performance. The conventional adaptive frequency hopping (AFH) strategies avoid frequency-static interference by reducing the hopset, but this deteriorates the performance if there is also self-interference. In this paper, we propose dynamic AFH (DAFH) mechanisms that are concurrently employed by collocated WPANs in order to avoid the self-interference. With DAFH, WPAN adaptively self-allocates a subset of frequency channels to be hopped, such as to minimize the experienced interference. The packet error rate is the only input to the proposed mechanisms, which enables DAFH to also avoid interference from frequency-static interferer. The optimization of the throughput should not be the sole target of the DAFH because WPAN operates in unlicensed spectrum and arbitrary adaptation of the FH pattern may be harmful to proximate non-WPAN devices. Therefore, we define and adopt an etiquette rule to characterize the behavior of the collocated WPANs with DAFH as a single collective entity that produces interference. The operation of DAFH is robust and adaptive to the dynamic changes in the environment and to the noise errors in the channel. Simulation results show that DAFH significantly increases the throughput of the WPANs in presence of both self-interference and frequency-static interference, while the WPANs employ best effort to minimize changes in the overall interference pattern

The throughput of WPAN (Wireless Personal Area Network) based on Bluetooth was decided by the interference of Bluetooth piconets in the network. The interference was decided by the hamming correlation of Bluetooth FH (Frequency Hopping) selected sequence. In order to improve the WPAN throughput, the WPAN model and data packet collision model were built and the relations about WPAN throughput, the maximum hamming correlation of FH selected sequence, the numbers of Bluetooth piconets and the SNR of channel were analyzed. The functions of WPAN throughput were deduced. After analyzing the performance of Bluetooth FH selected sequence, the original algorithm was replaced by the AES (Advanced Encryption Standard) algorithm. The theoretical analysis proved that the AES FH sequences selected algorithm could improve the WPAN throughput. The simulation results proved the theoretical analysis. The test result with ARM926EJs SoC (System on Chip) + RF (Radio Frequency) chip nRF2401 and CSR's Bluecore4 Bluetooth module got the same conclusion. All of these could prove that the AES algorithm can improve the WPAN throughput efficiently.

Supporting multimedia traffic is one of the major challenges for the next generation of wireless personal area networks (WPANs). Especially, the IEEE 802.15.4 WPAN standards specify how to guarantee real-time traffic with a type of time division multiple access (TDMA), called the guaranteed time slots (GTS). The GTS mechanism has led many researchers to design techniques aiming to support various real-time applications within the delay jitter. Since the IEEE 802.15.4 standards can operate at low data rate up to 250Kbps, it is limited to guarantee real-time multimedia traffic except voice. The voice traffic has bidirectional characteristics and may go through the multihop in WPAN which can support short-range communications among electronic devices. In this paper, we introduce a virtual cut-through GTS allocation mechanism, namely VC-GTS allocation, for voice traffic in multihop IEEE 802.15.4 systems. The proposed scheme can support bidirectional voice traffic and delivery the traffic to the destination through multihop paths with the minimum end-to-end delay time. The most important thing is that our proposed scheme achieves low delay time and packet error rate without a complex allocation algorithm in multihop IEEE 802.15.4 networks. Our simulation results show that our new scheme outperforms the basic IEEE 802.15.4 GTS mechanism.

The wireless personal area network (WPAN) is an emerging wireless technology for future short range indoor and outdoor communication applications. The IEEE 802.15.3 medium access control (MAC) is proposed to coordinate the access to the wireless medium among the competing devices, especially for short range and high data rate applications in home networks. In this paper we use analytical modeling to study the performance analysis of WPAN (IEEE 802.15.3) MAC in terms of throughput, efficient bandwidth utilization, and delay with various ACK policies under error channel condition. This allows us to introduce a K-Dly-ACK-AGG policy, payload size adjustment mechanism, and Improved Backoff algorithm to improve the performance of the WPAN MAC. Performance evaluation results demonstrate the impact of our improvements on network capacity. Moreover, these results can be very useful to WPAN application designers and protocol architects to easily and correctly implement WPAN for home networking.

Problem statement: In universal networking environments; two or more heterogeneous communication systems coexisting in a single place. Especially, Wireless Local Area Networks (WLANs) based on IEEE 802.11b specifications and Wireless Personal Area Networks (WPANs) based on IEEE 802.15.4 specifications need to coexist in the same Industrial, Science and Medial (ISM) band. If the WPAN communication coverage is expanded using a cluster-tree network topology, then the 802.15.4 network is more susceptible to interference from neighboring WLANs. Approach: In this study, we propose an adaptive transmission power aware cluster scheduling algorithm using multiple channels in a WPAN in the presence of WLAN interference. Results: The algorithm includes node identification, channel allocation, clustering and time scheduling. To evaluate the performance of the proposed algorithm, the performance metrics such as Bit error, Packet Error Rate (PER), Throughput, Average End-End Delay and Average Jitter is measured through Qualnet simulation. PER is calculated from bit error rate. The simulation results are compared with the conventional TDMA scheme. Conclusion/Recommendations: The measurement result shows that the proposed algorithm is effective in an IEEE 802.15.4 cluster-tree network in the presence of multiple IEEE 802.11 interferers.

This paper proposes several extensions to IEEE Wireless Personal Area Network (WPAN) MAC protocol in order to enable a more robust and flexible solution to WPANs and sensor networks. Specifically, four extensions are proposed: a priority access period is added to handle emergency data transmission needed in some use cases, a scheduling protocol to resolve beacon transmission conflict between multiple WPANs operating in the same vicinity, a resource reservation protocol for interference- free data communication in a tree-topology WPAN, and a network alignment method to coordinate multiple coexisting unsynchronized WPANs.

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.

Scatternet formation is one of the most important issues of emerging wireless personal area networks (WPANs). Numerous papers pointed out that the performance of a WPAN highly depends on the scatternet structure; however, for next generation WPANs (IEEE 802.15.3 and 802.15.4) the issue of scatternet formation is not discussed in the literature so far. This paper presents the techniques, constraints and effects of scatternet formation. First, the theoretically based problem is formulated in integer linear programming (ILP) framework. Two heuristic methods are proposed for high-rate WPANs (802.15.3), which can be extended for low-rate WPANs (802.15.4) as well. The constructed networks are analyzed based on two metrics: (1) total network load, (2) amount of piconets. We show that network performance highly depends on the used algorithm: the network load can be reduced by up to 30% by using a proper scatternet formation algorithm. Furthermore, the scatternet can be optimized depending on the actual network traffic and individual objectives

In mobile wireless personal area networks (WPAN), the position of each node changes over time. A new network protocol that is able to dynamically update its links in order to maintain strong connectivity is said to be self-reconfiguring. In this paper, we propose mobile wireless personal area networks' (WPAN) design method with self-reconfiguring protocol for power efficiency. The WPAN is self-organized to clusters using an unsupervised clustering method, fuzzy c-means. A fuzzy logic system is applied to master/controller election for each cluster. A self-reconfiguring topology is proposed to manage the mobility and recursively update the network topology. We also modify the mobility management scheme with hysteresis to overcome the ping-pong effect.

This paper presents the calculation of the required bandwidth of common frequency bandwidth applying queueing theory for maximizing the efficiency of frequency resource of WPAN(Wireless Personal Area Network) based Digital acoustic and communication devices. It assumed that LBT device(ZigBee) and FH devices (DCP, RFID and Bluetooth) coexist in the common frequency band for WPAN based Digital acoustic and communication devices. Frequency hopping (FH) and listen before talk (LBT) have been used for interference avoidance in the short range device (SRD). The LBT system transmits data after searching for usable frequency bandwidth in the radio wave environment. However, the FH system transmits data without searching for usable frequency bandwidth. The queuing theory is employed to model the FH and LBT system, respectively. As a result, the throughput for each channel was analyzed by processing the usage frequency and the interval of service time for each channel statistically. When common frequency bandwidth is shared with SRD using 250mW, it was known that about 35 channels were required at the condition of throughput 84%, which was determined with the input condition of Gaussian distribution implying safety communication. Therefore, the common frequency bandwidth is estimated with multiplying the number of channel by the bandwidth per channel. These methodology will be useful for the efficient usage of frequency bandwidth.

Bluetooth Wireless Personal Area Networks (WPAN) is a new standard for low distance communications. In the WPAN, the time delay and bandwidth utilization are the bottleneck of network development. In this paper, an on-demand scheduling algorithm for time-sensitive transactions in the area of WPAN has been proposed. The algorithm referred in this paper is mainly composed of two important parts. On one hand, four final factors referred in the scheduling will be defined including data arrival rate, link load factor, data model factor and time factor. On the other hand, in order to meet the strict requirement of time delay, generally, the cluster identifier (CID) is a good aspect to be utilized to reduce the negative effect of time delay. However, different kinds of CID may have different priorities. The biggest advantages of this algorithm are low time delay and high band utilization. The feasibility of the algorithm can be demonstrated through the simulation.

The application of wireless personal area network (WPAN) and simple point-to-point wireless communication devices has increased drastically both in private household and in our workspaces in general over the last decade. Combined with the fact that the total number of wireless devices and associated standards present in the wireless environment is experiencing an extreme growth, the frequency spectrum scarcity is exposed as a severe challenge. Setting up efficient and reliable wireless WPAN links can be challenging even today. This is especially true because of the intensive use of the license-free frequency bands, where the level of interference can be extremely high. Combined with the challenges associated with multi-path propagation and attenuation, setting up and maintaining an acceptable level of perceived QoS is a challenging job even for trained professionals. This paper discusses the challenges associated with the implementation of highly reliable low-power WPAN networks for the future and the adaption of Cognitive Radio technology as a potential solution. A brief status on the maturity of CR technology will be presented as an integral part of this discussion.

Multimedia applications place high demands on resources in wireless networks. The 60GHz frequency band has been adopted to support high data rate applications in wireless personal area networks (WPANs). In the IEEE 802.15.3c standard for millimeter-wave-based high-rate WPANs, devices are allocated a dedicated transmission time called a CTA (channel time allocation) based on their request to transmit. While the duration of a CTA may be adjusted, the standard does not specify how resource allocation should be achieved. High-Definition (HD) video with variable bit rate (VBR) is a potential application for the WPAN. In this work, an IEEE 802.15.3c network is simulated and the throughput losses due to static resource provisioning for a series of H.264/SVC (MPEG-4 Part 10) HD video sources are identified. It is demonstrated that the high data rates proposed for the 60GHz frequency band will not be achieved without dynamic resource allocation.

The use of chirp-managed lasers (CML) for the distribution of OFDM-UWB radio signals in long-reach fiber-to-the-home passive optical networks (LR-PONs) is a cost-effective solution to extend the coverage of these signals in future wireless personal area networks (WPAN). Through numerical simulation, this paper analyzes the feasibility of the distribution of OFDM-UWB radio signals in LR-PONs using CML. The performance degradation of the transmission of OFDM-UWB signals is assessed in terms of the bit error ratio (BER) and, for a minimum BER of 10−4, the CML-based transmission achieves an improvement of 11 km in the maximum transmission distance compared to the use of a directly modulated laser.

Ultra-wideband (UWB) communications has emerged as a promising technology for high data rate wireless personal area networks (WPANs). In this paper, we address a key issue that impacts the performance of multi-hop, multi-rate UWB-based WPANs, namely joint routing and rate selection. Arbitrary selection of routes (including direct links) and transmission rates along these routes results in unnecessarily long channel reservation time and high blocking rate for prospective reservations, and leads to low network throughput. To remedy this situation, we propose a novel overhearing-aware joint routing and rate selection (ORRS) scheme, which improves the network throughput by exploiting the dependence between the channel reservation time and the multi-rate capability of an UWB system. At the same time, ORRS takes advantage of packet overhearing, a typical characteristic of broadcast communications. For a given source-destination pair, ORRS aims at selecting a path and its transmission rates that achieve the minimum reservation time, leading to low blocking rate for prospective reservations and high network throughput. We show that achieving this goal while simultaneously exploiting packet overhearing and satisfying a target packet delivery probability over the selected route leads to an NP-hard problem. Accordingly, ORRS resorts to approximate solutions (proactive and reactive) to find a near-optimal result with reasonable computational/communication overhead. We further propose other variants that exploit packet overhearing in different ways to improve ORRS performance.