Andrew Seybold on the shifting interface between radio and wiring experts and the internet side of the wireless world: andrewseybold.com
<<Tuesday, September 08, 2009
Historically, wireless networks have been designed and built by people who have skills in both the science and art of wireless. Wireless systems were built with racks of radio equipment, towers, and antennas, and connected back to dispatch or network centers with wired or microwave connections. When there was a problem, a radio technician was dispatched to the site with test equipment, tools, and spare parts.
Today a new battle is brewing. We are using the same towers, antennas, and feed lines, and the radio equipment is still mounted in racks. But the racks are smaller and the connections to the rest of the system are via T1, frame relay,fiber, or microwave links. But when there is a failure, typically, a technician is dispatched to the site after someone monitoring the system remotely has run diagnostics and isolated the point of failure. The technician takes spare plug-in cards with him/her, and "repairs" the system by replacing a bad card or sub-module. Once the part has been replaced, remote diagnostics and a series of tests are run to confirm that the system is back in full operation.
Only a few years ago, we developed site coverage plots by hand, using complex formulas that yielded approximate answers for coverage from specific locations for a specific type of radio service. Today we use complex computer software. We enter the perimeters and the software draws all kinds of fancy plots and we end up with approximate answers for coverage from specific locations.
Today we are heading for a new world where wireless collides with IP and Internet technology. It has been coming for a long time but now it is accelerating and the implications will be interesting. Back when I was helping LA County deploy its microwave backbone for its radio, telephone, and 911 systems, we put large dish antennas on the towers, ran huge cables down to the communications building, attached them to racks full of radio equipment, and interfaced the systems to wired T1 and other types of wired backbone.
Today, someone climbs the tower, clamps a small dish antenna to the side of it, and plugs in an RJ-45 connector attached to a piece of Ethernet cable that runs into the communications shelter where it is plugged into an IP router and then connected to the wired network. By the way, both types of systems work just fine. The newer ones are a lot less expensive to deploy, and when they break they are not fixed in the field, as the older systems were. Boards are replaced until the system starts working again.
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Sure enough, in the Zenbu world, people with no expertise buy a router on-line, plug it into their broadband and away they go. Some of them are now increasing coverage greatly by buying a Ubiquiti NanoStation2 access point which can be installed 100 metres away with a power over ethernet link back to base. They simply plug it in and it works. Available here: gowifi.co.nz
The level of expertise needed in the field is very low to get a good enough job. The equipment costs are low NZ$249 for the Zenbu router and NZ$210 for the NanoStation2 [cable about $1 a metre]
People building wide area networks with Wi-Fi still need some expertise, but it's getting easier and cheaper.
Mqurice |
