Fast handoff support is a basic requirement for an Internet-based wireless mesh network (WMN), aiming to guarantee mobile users to be continuously connected to the Internet, regardless of their physical locations or moving trajectory. Due to the multi-hop transmission of network-layer handoff signaling packets, handoff performance in WMNs can be largely degraded by the increasing number of wireless hops as well as the channel access contentions between data and signaling packets in the mesh backbone. However, these issues are ignored in existing handoff solutions and multi-channel medium access control schemes. In this paper, we address the seamless handoff support from a different perspective and propose a gateway scheduling-based handoff scheme in single-radio multi-hop WMNs. Our proposed handoff scheme can realize single-hop handoff signaling packet transmissions and eliminate the channel contentions between data and signaling packets. Simulation results show that the total handoff delay is improved significantly using our proposed gateway scheduling-based handoff scheme under various scenarios, as compared to existing handoff solutions in multi-hop WMNs. In addition, due to the single-hop transmission of signaling packets, the signaling overhead in the wireless mesh backbone can be substantially reduced.

Seamless handoff support is an essential issue to ensure continuous communications in multi-hop wireless mesh networks (WMNs). Due to the multi-hop transmission of network-layer handoff signaling packets, the handoff performance in WMNs can be largely degraded by the long queueing delay and medium access delay at each mesh router, especially when the backbone traffic volume is high. However, this issue is ignored in existing handoff solutions and multi-channel allocation schemes. In this paper, we address the seamless handoff support from a different perspective and propose a novel channel allocation design in hierarchical WMNs to reduce the queueing delay and medium access delay of handoff signaling packets over multi-hop wireless links and to improve the average channel utilization simultaneously. Both analytical and OPNET simulation results show that the performance of the average channel utilization and total handoff delay can be improved significantly using our proposed channel allocation scheme under various scenarios, as compared to other existing channel allocation and handoff solutions in multi-hop WMNs.

Handoff delay is a key metric to evaluate the performance of wireless mesh networks (WMNs). Since data packets and handoff signaling packets are transmitted on the same backbone channel in single-channel single-radio based WMNs, the channel contentions between data and signaling packets often lead to long signaling packet queueing delay and channel access delay. Therefore, the handoff performance is largely determined by the backbone data traffic volume. However, this important issue is ignored by existing handoff solutions in multi-hop WMNs. In this paper, we consider to reduce the handoff delay in single-backbone-channel-based WMNs from a different perspective and propose a contention-based time division (ConT) scheme to shorten the channel access delay and queueing delay of handoff signaling packets over multi-hop wireless links. Simulation results show that the multi-hop handoff performance can be improved significantly without undermining the data throughput by our proposed ConT scheme.

Seamless handoff support is an essential issue to ensure continuous communications in multi-hop wireless mesh networks (WMNs). Due to the multi-hop transmission of network-layer handoff signaling packets, the handoff performance in WMNs can be largely degraded by the long queueing delay and medium access delay at each mesh router, especially when the backbone traffic volume is high. However, this issue is ignored in existing handoff solutions and multi-channel allocation schemes. In this paper, we address the seamless handoff support from a different perspective and propose a novel channel allocation design in hierarchical WMNs to reduce the queueing delay and medium access delay of handoff signaling packets over multihop wireless links and to improve the average channel utilization simultaneously. Both analytical and OPNET simulation results show that the performance of the average channel utilization and total handoff delay can be improved significantly using our proposed channel allocation scheme under various scenarios, as compared to other existing channel allocation and handoff solutions in multi-hop WMNs.

Seamless handoff support is an essential issue to ensure continuous communications in wireless mesh networks (WMNs). Due to the existence of multi-hop wireless links, traditional handoff schemes designed for single-hop wireless access networks can hardly guarantee the low handoff latency requirement in WMNs. Existing solutions on reducing the handoff delay in WMNs ignore one important factor for the long handoff delay: the channel access delay of handoff signaling packets over the multi-hop wireless mesh backbone network. Various WMN channel assignment algorithms are designed to optimize the performance of data packets, but they do not address how to resolve the contentions between data packets and handoff signaling packets. In this paper, we propose a novel channel assignment algorithm in WMNs to reduce the channel access delay of handoff signaling packets over multihop wireless links. In addition, handoff solutions under the new channel assignment scheme are proposed. OPNET simulation results show that handoff performance can be improved by our proposed handoff schemes, as compared to existing solutions.

Seamless handoff support is an essential issue to ensure continuous communications in wireless mesh networks (WMNs). Due to the existence of multi-hop wireless links, traditional handoff schemes designed for single-hop wireless access networks can hardly guarantee the low handoff latency requirement in WMNs. Existing solutions on reducing the handoff delay in WMNs ignore one important factor for the long handoff delay: the channel access delay of handoff signaling packets over the multi-hop wireless mesh backbone network. In this paper, we address the seamless handoff issue in WMNs from a different perspective and propose a channel splitting strategy to reduce the channel access delay of handoff signaling packets over multi-hop wireless links. Based on the proposed channel splitting strategy, the handoff procedures and two transmission strategies for scheduling the delivery of handoff signaling packets are designed. Simulation results show that using the proposed channel splitting strategy, the handoff delay requirement in WMNs can be guaranteed regardless of the background data traffic, and the channel throughput can also be improved.