Q: Are you aware of any means - hardware 'dongle' or whatever - that would let you connect Wi-Fi antennas within a building to an access point via twisted pair cable? It would seem logical to use existing wired infrastructure to cover a large work floor with multiple antennas instead of multiple access points. Even if the price point for an extended antenna was the same as for an access point, you'd still only have to manage one access point instead of several. I realise that more access points means more simultaneous users, but to support a handful of users throughout a large building, this might be a possible solution. Any thoughts?
- Steve, St. Louis
The Wizards gaze deeply into their crystal ball, and note the similarity between what you suggest and the MobileAccess solution in use at Lehman Bros (this doesn't reduce the number of APs, but centralises them by decoupling them from their antennas). Here are their other thoughts:
Scott Haugdahl, WildPackets
Connecting a long run of twisted pair would “de-tune” the antenna and radiate part of the energy along the twisted pair. While there are antenna systems designed to do this (to cover hospital hallways and corridors for instance) it does not appear to be suitable for your application.
Have you considered alternatives to achieve your basic requirements of one access point, large building, few users? New Smart Array antennas used in conjunction with wireless switches provide a much more focused array of coverage for multiple users over larger distances (up to 300 meters) [However, these may not be available in the UK, owing to different radiocommunications regulations on radiated power density - Ed]
If smart array antennas are not adequate (especially in environments with a lot of build-out and/or multiple floors), consider installing wireless bridges (or access points with bridge-mode capability) that act as repeaters and don’t require any wire to the access point. Another possibility is to use a single access point (be sure to have a hot standby) in a centralised location and replace the two diversity antennas with two strong omni-directional antennas (so you can best orient the coverage vertically and horizontally) and use wireless repeaters to fill the voids.
Rich Swier, Highwall Technologies
The reason why you don’t see this type of product in the Wi-Fi space is because there is very little power allotted by the FCC to be used in a transmit/receive device, such as an access point. The loss of the power travelling over the wire and to multiple antennas would decrease the range of the signal dramatically. Even 10 feet of cable between and antenna an access point can reduce the range over 50 percent.
Michael Montemurro, Chantry Networks
The frame format for WLAN (802.11) and Ethernet (802.3) are different, so you could not send raw 802.11 traffic over a traditional twisted pair network (it would need dedicated wires). A WLAN access point acts as a bridge between the 802.11 network and the 802.3 Ethernet network. In larger installations, you will need to add more access points to provide coverage. However, as you add more access points, the management overhead increases because each access point acts a separate network element.
There are systems in the market today that address the management issues when you deploy a number of access points. They rely on a central controller that provides a single point of management for the entire wireless network. With some products, an access controller could sit deep in the wired network and provide a single point of administration for all access points. The access points could be positioned anywhere in the wired infrastructure that is routable back to the access controller. These systems provide centralised management, centralised security and mobility.