Bandwidth Estimation for Admission control in MANET: Review and Conceptual MANET Admission Control Framework

Mobile ad-hoc network (MANET) is one of the main technologies for the next generation wireless networking because of the positive impact it poses over other wireless networks having undergone rapid progress, which has inspired many applications. However, providing quality of service (QoS) assurance to MANET is hard because of the unpredictable nature of the wireless medium, contention problem amongst the channel, mobility problem and lack of central co-ordinator. Admission control is therefore seen as one of the methods for providing QoS. Admission control aim at estimating the network resource states and decides whether to admit a session without assuring more resources bandwidth space than what is available to avoid the violation of any rules that has been previously made. Some recent solution considered the MAC layer back-off impact due to collision as well as the non-synchronization between the sender and receiver when estimating the available bandwidth. None of the previous work proposed a technique that sends a HELLO packet to its one-hop neighbours which further aggregates to the rest of the nodes to retrieve the available bandwidth on a carrier sensing region, in order to limit the impact of additional overhead of the carrier sensing multiple access with collision avoidance (CSMA/CA). Also, none of the existing solution has properly addressed the channel idle time dependency between the sending node and the receiving node by differentiating the BUSY state from the SENSE BUSY states and the IDLE state caused by an empty queue. This paper, therefore reviews the bandwidth estimation techniques for admission control for MANET. The bandwidth estimation techniques for admission control have been categorized into two: active and passive estimation. An outline of each technique has been discussed as well as the proposed conceptual framework. The contribution as identified in this research work is the proposal of conceptual framework that adapts the following into the bandwidth estimation for admission control in MANET: (1) HELLO packet advertisement to one hop which further aggregates to retrieve the available bandwidth on the carrier sensing region, (2) Considering the channel idle time measurement by differentiating the channel busy state from channel sensing state and regarding an empty queue as an idle state. Future research directions are also outlined.