Wireless Network Optimisation Mike Morgan

Categories of Wireless Device ➲ Fixed ● Physically fixed in position e.g. Antenna mounted on tower or rooftop ● Commonly used for broadband communications ➲ Portable ● Stays in place while being used, but can be picked up and moved to another location ➲ Mobile ● In motion during use

Fixed Wireless Network Types ➲ Point to Point ● Bus Topology ➲ Point to Multipoint ● Star Topology ➲ Consecutive Point ● Ring topology: some redundancy ● Hamiltonian Cycle ➲ Mesh ● Mesh Topology: better redundancy ● Design problem is very complex

Mesh Networks ➲ How many different ways can these nine devices be connected? ➲ Which one is the best?

Design of Mesh Networks ➲ Some devices perform the task of 'relaying' data on behalf of others. ➲ The equipment needed for relay devices is normally far more expensive than for ordinary terminals. ➲ Two design goals: ● The number of relays used ought to be kept to a minimum. ● The network should provide adequate redundancy and be able to handle traffic demands.

Heuristics ➲ It is not possible to evaluate all possible mesh structures within a useful time frame ➲ A smaller subset of possible network designs must be evaluated. Optimal answers cannot be guaranteed. ➲ How might it be possible to select good designs for evaluation among so many alternatives?

Construction methods ➲ Greedy construction searches build the network component by component. ● Start with nothing and add relays in until all objectives are satisfied. ● Start with a maximum number of relays and drop as many as possible without violating constraints ➲ These searches can be adapted using iteration, random factors and memory based techniques.

Perturbation Methods ➲ Make minor alterations to a current solution in the hope of finding an improvement. ➲ Also may be adapted using random factors and memory. ➲ Useful as a means of improving already promising solutions