Cross-layer cut-through switching mechanism for IEEE 802.16d/e wireless networks

This paper proposes a fast cross-layer cut-through switching mechanism (CCSM) for supporting media access control (MAC) layer packet switching in IEEE 802.16-based broadband wireless access (BWA) networks. The local traffic, which means subscriber stations (SSs) communicating with each other within the cell, can be switched via the MAC layer without involving the network layer. The average access delay of request from SSs is studied and analyzed in this paper. Finally, the simulation and numerical results show that the performance of CCSM is superior to that of the legacy IEEE 802.16d/e protocol.     

Predictive Dynamic Channel Allocation Scheme for Improving Power Saving and Mobility in BWA Networks

The radio spectrum of IEEE 802.16 medium access control (MAC) protocol ranges from 2–66 GHz, which is one of potential solutions for broadband wireless access (BWA) or beyond third generation (B3G)/4G networks. The maximum transmission range can reach about 48 km. However, with the property of radio propagation, the maximum transmission distance is proportioned inversely to the frequency the mobile subscriber station (MSS) carries. According to this property, the channel allocation can be based on how far the distance between the MSS and the base station (BS) in a macrocell. Therefore, this paper first proposes a new concept of channel allocation model for BWA system and investigates the relations between the signal propagation and the distance as well as propose a signal-aware dynamic channel allocation (SDCA) scheme for dynamic channel allocation (DCA) in BWA networks (BWANs). The SDCA enables the BS to allocate appropriate channels to MSSs according to the received signal-to-noise ratio (SNR) value from the MSSs. Besides, according to the frequency, the SDCA can estimate a minimum power for MSS to communicate. The SDCA not only increases the capacity of the system but saves the overall power consumption of the system well. We also present a new out-of-service prevention scheme for supporting mobility in the system. Simulation results show that the proposed SDCA can achieve the channel utilization (throughput) by up to 94.4% when the spectrum ranges from 2–11 GHz.

High Performance Wireless Switch Protocol for IEEE 802.11 Wireless Networks

All mobile stations (STAs) in IEEE 802.11 infrastructure wireless local area networks (IWLAN) are coordinated by an access point (AP). Within the 2.4 GHz unlicensed industry, science, and medicine (ISM) band defined in the IEEE 802.11 2.4 GHz physical layer (PHY) specifications, three channels are available for concurrently transferring data packets at the coverage area of an AP. In most of small/medium enterprises or home environments, an AP with one selected channel is sufficient for covering whole service area, but this implies that the radio resources for the remaining two channels are wasted. In order to overcome the drawback, we propose a new and simple media access control (MAC) protocol, named wireless switch protocol (WSP), for increasing the throughput of IEEE 802.11 IWLAN network to support high quality multimedia traffic. This is achieved by allowing any pair of STAs in IWLAN to exchange data packets in one of other idle channels after their handshake with each other in the common channel controlled by AP. Simulation results show that the total network throughput of WSP depends on the time taken by channel switching, and on the ‘Intranet’ and ‘Internet’ traffic distribution, where the Intranet and Internet mean data transmission between STAs in IWLAN and between the STA and wired host, respectively. When all data packets are Intranet traffic and the traffic load is heavy, the ratio of Goodput for the proposed WSP to that of IEEE 802.11 standard approximates 400%. In the worse case of all Internet traffic, the proposed WSP still obtains the similar throughput as that of IEEE 802.11 standard.Jenhui Chen was born on October 12, 1971 in Taipei, Taiwan, Republic of China. He received the Bachelor’s and Ph.D. degree in Computer Science and Information Engineering (CSIE) from Tamkang University in 1998 and 2003, respectively. In the Spring of 2003, he joined the faculty of Computer Science and Information Engineering Department at Chang Gung University and served as the Assistant Professor. He occupies the supervisor of Network Department in the Information Center, Chang Gung University. Dr. Chen once served the reviewer of IEEE Transactions on Wireless Communications, ACM/Kluwer Mobile Networks and Applications (MONET), and Journal of Information Science and Engineering. His main research interests include design, analysis, and implementation of communication and network protocols, wireless networks, milibots, and artificial intelligence. He is a member of ACM and IEEE.Ai-Chun Pang was born in Hsinchu, Taiwan, R.O.C., in 1973. She received the B.S., M.S. and Ph.D. degrees in Computer Science and Information Engineering from National Chiao Tung University (NCTU) in 1996, 1998 and 2002, respectively. She joined the Department of Computer Science and Information Engineering, National Taiwan University (NTU), Taipei, Taiwan, as an Assistant Professor in 2002. Her research interests include design and analysis of personal communications services network, mobile computing, voice over IP, and performance modeling.Shiann-Tsong Sheu received his B.S. degree in Applied Mathematics from National Chung Hsing University in 1990, and obtained his Ph.D. degree in Computer Science from National Tsing Hua University in May of 1995. From 1995 to 2002, he was an Associate Professor at the Department of Electrical Engineering, Tamkang University. Since Feb. 2002, he has become a Professor at the Department of Electrical Engineering, Tamkang University. Dr. Sheu received the outstanding young researcher award by the IEEE Communication Society Asia Pacific Board in 2002. His research interests include next-generation wireless communication, WDM networks and intelligent control algorithms.Hsueh-Wen Tseng received his B.S. degree in electrical engineering from Tamkang University, Taipei country, Taiwan, in 2001 and M.S. degree in electrical engineering from National Taiwan University of Science and Technology, Taipei, Taiwan, in 2003. He is currently pursuing the Ph. D. degree at the Department of Computer Science and Information Engineering, National Taiwan University, Taipei, Taiwan. His research interests include design, analysis and implementation of network protocols and wireless communications.     

MR2RP: The Multi-Rate and Multi-Range Routing Protocol for IEEE 802.11 Ad Hoc Wireless Networks

This paper discusses the issue of routing packets over an IEEE 802.11 ad hoc wireless network with multiple data rates (1/2/5.5/11 Mb/s). With the characteristics of modulation schemes, the data rate of wireless network is inversely proportional with the transmission distance. The conventional shortest path of minimum-hops approach will be no longer suitable for the contemporary multi-rate/multi-range wireless networks (MR²WN). In this paper, we will propose an efficient delay-oriented multi-rate/multi-range routing protocol (MR²RP) for MR²WN to maximize the channel utilization as well as to minimize the network transfer delay from source to destination. By analyzing the medium access delay of the IEEE 802.11 medium access control (MAC) protocol, the proposed MR²RP is capable of predicting the transfer delay of a routing path and finding the best one, which has the minimum transfer delay from source to destination. The proposed MR²RP may choose a longer path but with less contention competitors and buffer queuing delay. Simulation results show that MR²RP performs the load balancing and fast routing very well, and its call blocking probability is obviously lower than that of conventional minimum-hops approach with fixed transmission rate.An erratum to this article can be found at     

Editorial: Physical Layer Security and Wireless Access Control (QSHINE 2017)

Mobile Networks and Applications -