Capacity Of Mobile Ad Hoc Networks Research Articles

A QoS Routing Protocol with Bandwidth Allocation in Multichannel Ad Hoc Networks

Mobile multimedia applications have recently generated much interest in mobile ad hoc networks (MANETs) supporting quality-of-service (QoS) communications. Multiple non-interfering channels are available in 802.11 and 802.15 based wireless networks. Capacity of such channels can be combined to achieve higher QoS performance than for single channel networks. The capacity of MANETs can be substantially increased by equipping each network node with multiple interfaces that can operate on multiple non-overlapping channels. However, new scheduling, channel assignment, and routing protocols are required to utilize the increased bandwidth in multichannel MANETs. In this paper, we propose an on-demand routing protocol M-QoS-AODV in multichannel MANETs that incorporates a distributed channel assignment scheme and routing discovery process to support multimedia communication and to satisfy QoS bandwidth requirement. The proposed channel assignment scheme can efficiently express the channel usage and interference information within a certain range, which reduces interference and enhances channel reuse rate. This cross-layer design approach can significantly improve the performance of multichannel MANETs over existing routing algorithms. Simulation results show that the proposed M-QoS-AODV protocol can effectively increase throughput and reduce delay, as compared to AODV and M-AODV-R protocols.

A new distributed cooperative MIMO scheme for mobile ad hoc networks

In this paper, we introduce a new communication scheme based on cooperative multiple-input multiple-output (MIMO) communication for mobile ad hoc networks (MANETs) in which nodes are endowed with M antennas. According to our new approach, adjacent nodes no longer interfere with each other but rather cooperate attempting to communicate concurrently. In our scheme, during transmissions, the nodes send packets from only one of their antennas, while during reception, they use all of their antennas to receive and decode packets from multiple close nodes simultaneously. Therefore, each distributed MIMO system in this scheme consists of multiple transmitting nodes acting as a single-array of multiple antennas. We derive upper and lower bounds on the receiver node ergodic capacity in the network where the wireless channel is modeled with both large and small-scale fluctuations. These bounds are compared with Monte-Carlo simulation of point-to-point and cooperative MIMO communications in MANETs. We demonstrate that the capacity of MANETs with multiple antennas is improved using cooperation compared to non-cooperative schemes, i.e., point-to-point MIMO communication. In addition, under the above communication model, we demonstrate that the lower and upper bounds of the ergodic capacity grows linearly with the number of receiving antennas M.