Voice over WLAN is an extension of Voice over Internet Protocol, a technology that has already taken root in enterprise telecommunication services. This technology allows Voice communication services to be deployed on enterprise/campus networks using WLAN. The use of VoWLAN makes it possible for mobile employee of an enterprise to be provided with cost effective voice and flexible services. The services includes the possibility of making a one- to-one call within the network without using the PBX and yet at no cost to the enterprise. This is also possible with one – to – multiply voice call, where an employee can communicate with an entire department in a walki-talki style also with neither any service cost nor using the PBX. This Thesis work will focus on a proposed deploying VoWLAN on a WLAN architecture that meets the criteria for the Next Generation WLAN taking advantage of a combined Distributed and Centralised switching approaches, in order to ensure mobility within an Enterprise or Campus, efficiency, cost effectiveness, security of information within the network for both data and voice services, and efficient voice communications without undermining data communications.