Ok I seen here that someone was saying that CPCD was cheaper than Ham radio. CPCD costs $50.00 per month. - Ham radio is Free per month CPCD advantage.. bandwidth - this depends as in any radio data telemetry. their maximum bandwidth advertised is in perfect conditions next to the POE (Point Of Entry) the farther you get from that the more latency you expierience. the more degraded the signal the less bandwidth you have. CPCD disadvantage.. cost per month varies wildly from city to city. this service where I live is offered at $0.98 cents a minute. no flat fee access at all. the monthly access charge is high $49.95 with 10 free minutes! and this is local area only, a more expensive plan is available for statewide and nationwide roaming. Now a little lesson on radio transmissions and their effect on data bandwidth. With any data system, if the target is moving you can take your possible bandwidth and cut it by 1/2 if there are very few obstructions and reflective surfaces between the base and the target. This would be something like a rural area. Suburbs are close to the same while a densly populated city will cut the rate by 3/4 or more. Multipath is your enemy along with picket fencing. say you are transmitting at 56Kbps per second. you lost the signal for 10ms you just lost 5.6 bits which will require the re-transmission of the packet. now at 1.2Kbps you only lost 0.12 bits which could be ignored and or recovered in error correction. There are many things that WILL effect your data rate. when you look into these wireless commercial solutions ask 3 questions.. what is the highest data rate, the average for my city standing still, the average while moving. If they cant answer these questions find a different salesperson for that company.. they know this information, it is derived from the inital testing when the system is first put online. I hope this helps. -- Subcription/unsubscription/info requests: send e-mail with subject of "subscribe", "unsubscribe", or "info" toWear-Hard Mailing List Archive (searchable): http://wearables.ml.org
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