Wireless Communications and Mobile Computing

Cover image for Vol. 12 Issue 7

May 2012

Volume 12, Issue 7

Pages i–ii, 567–660

    1. You have free access to this content
      Issue Information (pages i–ii)

      Version of Record online: 10 APR 2012 | DOI: 10.1002/wcm.2172

  1. Research Articles

    1. Top of page
    2. Research Articles
    1. QoS-aware routing and power control algorithm for multimedia service over multi-hop mobile ad hoc network (pages 567–579)

      Zae-Kwun Lee, GyeongCheol Lee, Hyung Rai Oh and Hwangjun Song

      Version of Record online: 1 JUL 2010 | DOI: 10.1002/wcm.995

      Thumbnail image of graphical abstract

      QoS-aware routing and power control algorithm consuming low transmission power for multimedia service over mobile ad hoc network.

    2. Enhanced video phone services for NGN/IMS (pages 580–587)

      Gong-Da Fan, Chao-Chun Huang, Yi-Bing Lin, Chung-Shih Tang, Chin-Ywu Twu and Yun-Hui Wen

      Version of Record online: 1 JUL 2010 | DOI: 10.1002/wcm.997

      Thumbnail image of graphical abstract

      A Next Generation Network (NGN) has been developed in Taiwan, where IP Multimedia Subsystem (IMS) plays an important role to offer IP-based multimedia services. In this paper, we show how existing video phone service can be enhanced through Chunghwa Telecom's NGN/IMS. Specifically, we illustrate three examples including Multimedia on Demand (MOD) TV, Multimedia Ringback Tone (MRBT) and Easy Go (EzGo). We also measure the delay times for accessing these services, which indicates that performance for these IMS-based services is satisfactory.

    3. Unified fixed-point analysis of IEEE 802.11 WLAN under saturated and unsaturated conditions (pages 588–597)

      Hui Yu, Luoyi Fu and Youyun Xu

      Version of Record online: 1 JUL 2010 | DOI: 10.1002/wcm.998

      Thumbnail image of graphical abstract

      For IEEE802.11 WLAN, Bianchi's Markov back-off model has been extended to unsaturated condition and analyzed by renewal-reward theorem. The fixed-point solution is provided along with the condition to guarantee both uniqueness and balance. In the case of large number of nodes, the closed-form formulas are provided for collision probability, aggregate attempt rate, and throughput. The proposed analysis based on unsaturated condition covers the saturated condition as well.

    4. Splitting downlink multimedia traffic over WiMAX and WiFi heterogeneous links based on airtime-balance (pages 598–614)

      Jong-Ok Kim, Peter Davis, Tetsuro Ueda and Sadao Obana

      Version of Record online: 26 JUL 2010 | DOI: 10.1002/wcm.999

      Thumbnail image of graphical abstract

      This paper proposes an airtime-balanced traffic split mechanism. IP packets are distributed to multiple RATs (Radio Access Technologies) so that airtime is equally balanced between RATs. A practical test-bed system was implemented, including WiMAX and WiFi, and experimental results confirm its usefulness.

    5. MAX–MIN aggregation in wireless sensor networks: mechanism and modeling (pages 615–630)

      Hanlin Deng, Baoxian Zhang, Cheng Li, Kui Huang and Haitao Liu

      Version of Record online: 26 JUL 2010 | DOI: 10.1002/wcm.1000

      Thumbnail image of graphical abstract

      To suppress the redundant data transmissions in the process of MAX—MIN aggregation in wireless sensor networks (WSNs), we propose an effective data gathering mechanism, which is called SMMA. SMMA aggregates data in an energy-efficient manner and outputs the accurate result. We mainly measure the performance of different versions of SMMA in terms of average number of suppressed redundant data transmissions in a round of data gathering.

    6. Adaptive concentric chains protocol for energy efficient routing in wireless sensor networks (pages 631–651)

      Yih-Chuan Lin and Kai-Wei Jiang

      Version of Record online: 1 JUL 2010 | DOI: 10.1002/wcm.1001

      Thumbnail image of graphical abstract

      To conserve energy consumption in wireless sensor networks, instead of the nearest neighbor policy, Boundary First PEGASIS (BFP) protocol adopts a constrained networking approach that constructs multiple concentric chains under two chaining constraints. First, the orientation of the concentric chains should toward to the position of base station. Second, to select all the cluster heads (CHs) should consider the numbers of active nodes in all the chains.

    7. Performance of MIMO cross-layer MAC protocol based on antenna selection in ad hoc networks (pages 652–660)

      Wei Fang Mao, Walaa Hamouda and Iyad Dayoub

      Version of Record online: 1 JUL 2010 | DOI: 10.1002/wcm.1002

      Thumbnail image of graphical abstract

      To solve the node blocking problem associated with the IEEE 802.11 MAC protocol, the proposed protocol leverage the available degrees of freedom offered by the MIMO system to allow neighboring nodes to simultaneously communicate.