19 NOV, 2003 - 1135 CST Below, are some of the technical details of the planned expansion of the Cape Girardeau, MO BPL system. Apparently this system will use repeater units every 800 ft. in order to maintain signal strength - a guaranteed method for making sure the RF interference level stays constant, and one that poses a significant installation and maintenance cost increase. 73 - Dick, W9GIG ===================================================================== Ameren is still interested in a wireless solution because of the difficulty in planning all of the Concentrator and Repeater locations. Keith Brightfield is a Project Manager for Ameren Strategic Projects and is also the Chairman of the Power Line Communications Association. Ameren realizes that they do not know everything about wireless, ISP, etc and have assembled a team of experts to help them. The Ameren pilot started 2 years ago with a meeting at a Florida convention where MainNet connected with Keith who was an SBC Financial person at the time. Their pilot started as a 5 home trial in Crestwood and now includes 300 devices with 53 homes in Cape Girardeau. Ameren is presently using Gen 1 equipment which is delivering 300-800 Kbps to end users. Apparently a single device is capable of using a complete T1 bandwidth. The Generation 2 equipment is capable of triple that bandwidth but will not be used in Cape Girardeau. Ameren is only going after existing dial up users and not DSL or cable users. They want to deploy in strip malls also. The MainNet Concentrator Unit (CU) (~$200) is limited to T1 bandwidth and needs a $400 Cisco router. The CU can address about 50 end users and 256 repeaters. Repeaters are used every 800 cable feet and are magnetically coupled to medium and low voltage 2 or 3 phase lines. I saw a 4" cube which was the LV coupler (~$100 x2 or x3) and a larger highly insulated MV coupler (also ~$100 x2 or x3). There can be a maximum of 3 repeaters in a given chain before there needs to be another CU. They are planning between 89-100 CU for the Cape system. There are visions of expanding to the whole Ameren territory of parts of Missouri, Illinois, and Kentucky if the marketing test pans out. They apparently hired a University of Illinois professor from Carbondale who came out, during the 5 home or 300 device test, took some measurements and refuted the claims of interference from the hams. There is a single connection for a repeater at the power line which brings up the question about the power output and receiver sensitivity to get an idea of the isolation. Ameren has that data but did not offer it. It turns out that 40% of the homes need to have a repeater unit at the house to provide enough signal in the house outlets. A given MV to LV transformer handles between 0-7 homes with 3-5 being average. At the house there is an MSA (Meter Socket Adapter) which can house a repeater between the house and the power meter. Ameren management ultimately wants to use BPL or the wireless system to remotely control Cap bank switching and other monitoring but is not being allowed to use this as part of the initial justification. They are concerned about their tariffs and rate structures being affected by users paying for power lines that are used for Ameren non-power related profits. The Repeater and Subscriber unit look exactly the same. They are about 8 x 10 x 2 and have Ethernet, USB, RJ11 telco connectors. =====================================================================