Air Interface Specification Research Articles

Design of Software-Defined Radio Channel Simulator for Wireless Communications: Case Study With DSRC and UWB Channels

The software-defined radio (SDR) channel simulator is designed for testing the baseband transceiver of various wireless communication systems. The SDR architecture and the reconfiguration scheme used for changing the channel conditions and reconfiguring the hardware of the processing modules in the SDR channel simulator are presented. The simulator is capable of simulating four multipath fading channels and dedicated fading channels operating in various air interface specifications of wireless communication systems according to the demands of users. An example of the SDR channel simulator implemented with the air interface standards of dedicated short-range communications (DSRC) and ultrawideband (UWB) systems is carried out to observe the characteristics of two multipath fading channels and the hardware reconfiguration capability of processing modules and validate its correctness. The functions of the proposed SDR channel simulator can be extended to other new or modified air interface specifications of wireless communication systems without any hardware modification.

Performance Optimization for Delay-Tolerant and Contention-Based Application in IEEE 802.16 Networks

IEEE 802.16 standard suite defines the air interface specifications for fixed and mobile broadband access in wireless metropolitan area networks. Although the IEEE 802.16 MAC has been well defined by various bandwidth allocation and scheduling mechanisms to support QoS for different applications, efficient bandwidth allocation still remains as an open issue. We analyze and develop a mathematical model to evaluate the performance of the contention-based and delay-tolerant applications in IEEE 802.16 networks. We focus our attentions on allocating the uplink bandwidth efficiently, the basic goal is to optimize the performance with an optimal bandwidth allocation mechanism. The results of our analysis lay out clearly that a maximum uplink throughput and a minimum number of pending bandwidth request transmission can always be acquired by optimizing the contention period size in a frame. This optimal size is also influenced by the number of terminals in the network, which is also analyzed in the later part of the paper. Our results can be used for providing probabilistic throughput guarantee and determining the optimal contention period.

Queue-aware uplink bandwidth allocation and rate control for polling service in IEEE 802.16 broadband wireless networks

IEEE 802.16 standard defines the air interface specifications for broadband access in wireless metropolitan area networks. Although the medium access control signaling has been well-defined in the IEEE 802.16 specifications, resource management and scheduling, which are crucial components to guarantee quality of service performances, still remain as open issues. In this paper, we propose adaptive queue-aware uplink bandwidth allocation and rate control mechanisms in a subscriber station for polling service in IEEE 802.16 broadband wireless networks. While the bandwidth allocation mechanism adaptively allocates bandwidth for polling service in the presence of higher priority unsolicited grant service, the rate control mechanism dynamically limits the transmission rate for the connections under polling service. Both of these schemes exploit the queue status information to guarantee the desired quality of service (QoS) performance for polling service. We present a queuing analytical framework to analyze the proposed resource management model from which various performance measures for polling service in both steady and transient states can be obtained. We also analyze the performance of best-effort service in the presence of unsolicited grant service and polling service. The proposed analytical model would be useful for performance evaluation and engineering of radio resource management alternatives in a subscriber station so that the desired quality of service performances for polling service can be achieved. Analytical results are validated by simulations and typical numerical results are presented.

Cdma2000/sup /spl reg// high rate broadcast packet data air interface design

The Third Generation Partnership Project 2 recently baselined the specification for a cdma2000/sup /spl reg// high-rate broadcast packet data air interface ("cdma2000 High Rate Broadcast-Multicast Packet Data Air Interface Specification", 3GPP2 C.50054). The standard allows high-speed delivery of packet data to multiple access terminals. The article describes the air interface design adopted by 3GPP2, and presents simulation results that predict the performance of the high-speed broadcast system.

Investigation of CDMA Air Interface and Protocols

This appendix deals with the Korean air interface standard, TTA-62, for CDMA Mobile Systems (CMS) [1]-[2]. The standard has been set up by Telecommunications Technology Association (TTA) which is a standardization organization in Korea [3]. This standard is an important specification that should be determined prior to the development of a digital cellular system. The CMS has been developed on the basis of this standard and the papers published in this special issue are the results of the CMS development. This appendix also describes the technical commonality of these papers. It covers the outline of the air interface and protocol specifications. The outline includes its major characteristics, radio protocol architecture, functionalties, and call processing. A comparison is also given between TTA-62 and IS-95 [4], a North American digital cellular standard.