Raj

My apologies, should have read what I wrote before I posted it. The Motorola p2p kits are in fact RF kits rather han microwave; there is a licenced and unlicenced version depending on your preferred frequency. I believe you are right, you do need a licence for microwave transmitters. Although the motorola wireless transmitters are RF they are not the same as 802.11a bridge kits. To clarify, I think the wireless RF kits I linked to in my last post are definately much better value than a licenced microwave bridge for this scenario. Raj

The wireless point to point bridge seems like the best idea in my opinion. This will be more economical in the long run as you won't have to pay for the running costs of another centrex setup or additional internet connectivity, you are also able to upgrade the speed of the link as your requirements change. You may also wish to consider the set-up times for all of these systems; in my experience of working with centrex I have found that a new site installation normally takes about 12 weeks if there is no existing 24 pair cabling in the office block. To achieve your desired functionality I believe you could put a VOIP server into your patch cabinet allowing up to 48 of your existing POTS copper telephone lines to be patched into the VOIP system, this could then be sent across the wireless bridge to VOIP phones at the desks of your office staff. It would seem pointless to convert the lines back to analogue phones at the other end considering the price of VOIP hardware. Whether the VOIP phones are wireless or not is completely up to you. Overall link speed is surprisingly not so much of a problem, your key consideration should be the latency of the link hardware; if you have a low latency link you will be able to send your phones over using VOIP. You have two main options in terms of low latency link hardware, these are microwave transmitters and line of sight lasers. It would be very ambitions to try and use a standard 802.11g access point for this type of link even with external directional aerials. Lasers are the best technology for high bandwidth and low latency, we tend to use 'LaserBit' equipment at 1Gbps with no issues; they do however have the obvious disadvantage of only working through line of sight. This may not be a concern immediately, however over time I have seen problems with trees, and insects / birds interrupting the signal transmission. I would personally use a wireless microwave link; these are expensive, but they can go reliably for several miles without direct line of sight. I would again recommend the Motorola units as they are very reliable, easy to install and use power over Ethernet. A great feature of these units is the fact that the Tx / Rx hardware is the same for all current models, the speed is simply controlled by a firmware upgrade - this means that you can purchase an upgrade to your wireless link if/when you need it without having the boxes on your roof replaced. The Motorola units are available from these guys: http://www.wifigear.co.uk/category.aspx?category=F1FFDB49-7647-4AE5-BF85-6321CAA5CED0 Advertising removed but rest left as it is good advice - Ben Enjoy! Raj