A cross-layer approach for QoS topology control in wireless ad hoc networks
- Authors: Rokonuzzaman, S. K. , Pose, Ronald , Gondal, Iqbal
- Date: 2009
- Type: Text , Conference paper
- Relation: TENCON 2009 - 2009 IEEE Region 10 Conference
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- Description: Wireless ad hoc networks using omni-directional antennas do not scale well due to interference between nearby nodes. Maintaining the QoS of the communications in this type of network is a difficult task. Using multiple narrow beam directional antennas alleviates this problem at the expense of connectivity. Multi-beam smart antennas allow the network topology to be adjusted dynamically by adjusting the beamwidth and beam directions to minimize interference and to maximize the number of possible concurrent network communications. This in turn helps to maintain the QoS of the communications. QoS routing has long been used to meet the user requirements by finding appropriate paths to the destinations. We extend this concept to create an adaptive QoS topology control (AQTC) system using smart antennas. We use a cross-layer approach to control the topology dynamically where the topology control layer sits between the MAC and the routing protocol. The performance of our protocol has been evaluated using extensive simulations. Simulation results show that different topologies for a set of communications perform differently. AQTC always forms a topology to facilitate the current communications and improves the network throughput and end-to-end delay.
A cross-layer approach for using multiple radio channels with directional beams in a suburban Ad Hoc network
- Authors: Rokonuzzaman, S. K. , Pose, Ronald , Gondal, Iqbal
- Date: 2008
- Type: Text , Conference paper
- Relation: Australasian Telecommunication Networks and Applications Conference
- Full Text: false
- Reviewed:
- Description: The capacity of wireless ad hoc networks can be increased by using multiple radio channels. But due to interference the capacity is still not fully utilized. This is caused by the limited number of available radio channels. The interference problem can be reduced using directional beams instead of omni-directional beams. This paper presents a novel cross-layer approach to use multiple radio channels with directional antennas. We are using three different radio channels. Each node has three fixed directional beams having fixed beamwidth and with different radio frequency. Two nodes can communicate when both the sending and receiving beams are pointing towards each other using the same frequency channel. In this study the directions of beams cannot be changed dynamically. A modified version of Ad hoc On-demand Distance Vector (AODV) routing protocol has been used. Simulation results show that our approach outperforms other methods using three different radio channels with omni-directional antennas
A framework for a QoS based adaptive topology control system for wireless ad hoc networks with multibeam smart antennas
- Authors: Rokonuzzaman, S. K. , Pose, Ronald , Gondal, Iqbal
- Date: 2008
- Type: Text , Conference proceedings
- Full Text: false
- Description: Wireless ad hoc networks are self-configurable distributed systems. One of the major problems in traditional wireless ad hoc networks is interference. The interference could be reduced using smart directional antennas. In this study, multibeam smart antennas have been used. When using this type of antenna, two nodes can communicate when both the sending and receiving beams are pointing towards each other. Also, a node can only communicate with a subset of nodes in its neighborhood depending on the number of beams and their beamwidth. Thus, the network topology needs to be dynamic in this case, and by controlling the topology network, performance can be increased. In this paper, we present a framework of a cross layer approach of topology control that interacts with the routing layer and MAC layer and meets the required QoS of different data streams. The approach is fully distributed. When the network is initialized, the algorithm builds an initial connected topology and the routing algorithm uses this topology to find paths for the current communications. Then, depending on the network scenario, current communications and the required QoS, the topology control layer changes the topology to optimize the network performance. This study concerns suburban ad hoc networks (SAHN) where nodes tend to be fixed and are aware of their locations.