Effect of relaying on capacity improvement in wireless local area networks

Wireless relay nodes can improve the capacity of wireless networks. In this work, we integrate wireless relay nodes into the infrastructure of a wireless local area network (WLAN). In particular, we investigate the effect of different relay strategies and optimal utilization of a fixed number of immobile relay nodes, which maximizes the expected throughput capacity of the network. We study how the number of relay nodes, the range of users, transmission power, path loss exponent, and traffic characteristics affect the optimal relay node placement and expected throughput capacity of the network. Our results show that a time-division relay strategy can far outperform a receive-and-retransmit relay strategy. Furthermore, for a wide range of system parameters, optimally placed relay nodes can significantly increase the network expected throughput capacity.

[1]  Junshan Zhang,et al.  Capacity Bounds and Power Allocation for the Wireless Relay Channel , 1990 .

[2]  Chun-Hung Richard Lin,et al.  Mobile multicast support in IP networks , 2000, Proceedings IEEE INFOCOM 2000. Conference on Computer Communications. Nineteenth Annual Joint Conference of the IEEE Computer and Communications Societies (Cat. No.00CH37064).

[3]  E. Meulen,et al.  Three-terminal communication channels , 1971, Advances in Applied Probability.

[4]  Ying-Dar Lin,et al.  Multihop cellular: a new architecture for wireless communications , 2000, Proceedings IEEE INFOCOM 2000. Conference on Computer Communications. Nineteenth Annual Joint Conference of the IEEE Computer and Communications Societies (Cat. No.00CH37064).

[5]  Jing Deng,et al.  Wireless ad hoc networks , 2003 .

[6]  Lachlan L. H. Andrew,et al.  Minimum power routing for multihop cellular networks , 2002, Global Telecommunications Conference, 2002. GLOBECOM '02. IEEE.

[7]  Wolfgang Zirwas,et al.  A Multi Hop Concept for HiperLAN/2: Capacity and Interference , 2001 .

[8]  Chunming Qiao,et al.  Integrated cellular and ad hoc relaying systems: iCAR , 2001, IEEE J. Sel. Areas Commun..

[9]  Frank H. P. Fitzek,et al.  Design and performance of an enhanced IEEE 802.11 MAC protocol for multihop coverage extension , 2003, IEEE Wireless Communications.

[10]  Adam Wolisz,et al.  Capacity Increase of Multi-hop Cellular WLANs Exploiting Data Rate Adaptation and Frequency Recycling , 2004 .

[11]  Seble Mengesha,et al.  Relay Routing and Scheduling for Capacity Improvement in Cellular WLANs , 2003 .

[12]  Cyril Leung,et al.  An overview of scheduling algorithms in wireless multimedia networks , 2002, IEEE Wirel. Commun..

[13]  Rene L. Cruz,et al.  Optimal routing, link scheduling and power control in multihop wireless networks , 2003, IEEE INFOCOM 2003. Twenty-second Annual Joint Conference of the IEEE Computer and Communications Societies (IEEE Cat. No.03CH37428).

[14]  Theodore S. Rappaport,et al.  Wireless communications - principles and practice , 1996 .

[15]  Hui Li,et al.  Multihop communications in future mobile radio networks , 2002, The 13th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications.

[16]  Abbas El Gamal,et al.  Capacity theorems for the relay channel , 1979, IEEE Trans. Inf. Theory.

[17]  Thomas M. Cover,et al.  Elements of Information Theory , 2005 .

[18]  Ashutosh Sabharwal,et al.  On capacity of Gaussian 'cheap' relay channel , 2003, GLOBECOM '03. IEEE Global Telecommunications Conference (IEEE Cat. No.03CH37489).