Colin Lemmon

Geographic Forwarding and Routing for Ad-hoc Wireless Network: A Survey

Routing for ad-hoc wireless network is challenging, and there is no single routing strategy to deal with the complex and dynamic nature of the ad-hoc network. Given the availability of the low cost of location-aware devices, geographic forwarding and routing provided opportunity for improving existing ad-hoc routing strategies. In this paper, geographic forwarding strategies and geographic routing protocols are reviewed; challenges of implementing geographic routing in ad-hoc network are identified and discussed. More research effort is called for improving the basic forwarding strategy to increase the efficiency of the geographic routing protocol to provide a practical solution addressing the issues related to routing around local minima.

Boundary Mapping and Boundary-State Routing (BSR) in Ad Hoc Networks

This paper presents a geographic routing protocol, boundary state routing (BSR), which consists of two components. The first is an improved forwarding strategy, greedy-bounded compass, which can forward packets around concave boundaries, where the packet moves away from the destination without looping. The second component is a boundary mapping protocol (BMP), which is used to maintain link state information for boundaries containing concave vertices. The proposed forwarding strategy greedy-bounded compass is shown to produce a higher rate of path completion than Greedy forwarding and significantly improves the performance of greedy perimeter state routing (GPSR) in sparse networks when used in place of greedy forwarding. The proposed geographic routing protocol BSR is shown to produce significant improvements in performance in comparison to GPSR in sparse networks due to informed decisions regarding the direction of boundary traversal at local minima.

Light-hearted negative terminology used in computer education and related skill of noncomputer users

Theory suggests that light-hearted but negative phrases and terminology used in computer literature and course titles may have a negative effect on noncomputer users. This study tested the effect of providing the suggestion of a negative dimension of computer ability labelled with a category of “Computer Dummy” and also the relation between computer ability and computer anxiety. The study incorporated 37 noncomputer users, 17 men and 20 women whose mean age was 52.1 yr. Scores on a self-report questionnaire indicated that 23 of the nonusers responded on the negative dimension of computer ability and included themselves in the category of “Computer Dummy.” Also, belief about ability and belief about computer training were associated with computer anxiety for noncomputer users.

Low resolution grid mapping approach for geographic routing

Handling local minima in geographical routing is of great importance since it is a core component in geographic forwarding processes. This paper proposes a new low-resolution grid occupancy mapping GOM approach to effectively handle local minima for existing geographic routing protocols. The proposed approach seeks to discover and distribute a low-resolution map containing anomalies in the coverage areas where potential local minima exist. This approach minimises overhead while maintaining minimal global knowledge to effectively route around local minima. Experimental results demonstrate significantly lower probe bandwidth and memory requirements in comparison to the previously proposed boundary mapping protocol BMP at the cost of an increase in hello message size. The proposed approach is well suited for scalable and dynamic mobile networks due to the reduction in probe and memory overhead and cellular structure. Future research includes improvements to the boundary detection algorithm and integration into existing geographic routing protocols.

Cooperative Behaviour of Location Aware Nodes in Ad-hoc Networks

This paper presents a method for packet delivery around voids in ad-hoc networks that use geographic forwarding. The use of local cooperative behaviours to transport packets around network voids features no global coordination. By changing goals, an individual node can create or join in a transient group that generates and holds local knowledge of the void, and which triggers modified behaviour for packet delivery. It is envisaged that additional behaviours may be developed to handle network operation at multiple protocol layers.