The VoWLAN approach also enables small and medium-sized businesses to cost-effectively establish mobile telephony inside their facilities. The cost for the equipment, including the installation of a wireless LAN, is much less expensive than establishing a local cellular system. The VoWLAN system, however, doesn’t generally support public roaming due to limited interoperability between different systems.
In order to deploy a VoWLAN solution, the enterprise purchases, installs and supports the system. There is generally no need to involve a carrier beyond the traditional fees for a connection to the PSTN, which means that there are no individual user service fees as there are with cellular. This savings often prompts companies to go with a VoWLAN system, but be careful to include all support costs before making the decision. Keep in mind that you’ll need to establish an applicable help desk and staff for troubleshooting problems that might arise.
Ensure that the wireless LAN offers adequate signal coverage throughout all areas where users need to make calls. In addition to work areas, this likely includes stairwells and possibly elevators, which are generally not covered well by existing wireless LANs. Signal strength throughout the coverage areas must be relatively high as compared to data-only wireless LANs. And, the network must have enough capacity to support the volume of anticipated calls. All of this often requires some re-engineering of the network and an accurate RF (radio frequency) signal assessment.
When deciding on which approach to use, certainly weigh the costs and benefits, but don’t forget how the end solution will impact users. With a VoWLAN system, for example, users will likely need to use a different phone to make calls when away from the facility, such as when traveling in a taxi to the airport. The VoWLAN industry is marching on and will probably include better interoperability and roaming in the future.
Also, the initial installation or upgrade of a wireless LAN that supports wireless telephony is somewhat complex and requires some definite RF experience. A problem is that most IT staff has very little experience with networks that support voice, making it a necessity to bring in experts. Don’t forget to include this cost – it’s well worth spending a little extra and significantly reduce risks of the system not working properly.
Jim Geier is the principal consultant of Wireless-Nets, Ltd. (www.wireless-nets.com), a consulting firm assisting companies with the implementation of wireless mobile solutions.