steck@aplcen.apl.jhu.edu (Steck Thomas) (04/11/90)
Something I've been wondering about lately... Cordless phones are a convenience and have many advantages over corded phones - mostly the lack of cord, and the increased mobility over a corded phone. The drawbacks - interference with other devices in the neighborhood on that frequency, florescent lamps, and signal interference from buildings, trees, etc. My proposal is this: why hasn't someone done this with digital signals? With the costs of digital technology plunging, and availability of digital components increasing, why hasn't someone put a sampler the handset, converted the signal into a digital stream (with error correction..) and send that to the base, which could then convert the digital stream to an analogg signal. Sounds like a good idea. Tom Steck
thurston%mrc-applied-psychology.cambridge.ac.uk@nsfnet-relay.ac.uk (04/11/90)
Steck Thomas writes: >With the costs of digital technology plunging, and availability of >digital components increasing, why hasn't someone put a sampler the >handset, converted the signal into a digital stream (with error >correction..) and send that to the base, which could then convert the >digital stream to an analogg signal. The proposed system exists and is sold in Britain under the umbrella name 'telepoint'. The handsets may be used at railway stations etc, in the vicinity of specially placed basestations ... the call is billed to you and is generally quite cheaper than using a cellphone. If you buy a home basestation you may use it as an ordinary cordless. Up to six handsets may be used with one basestation, you may call between handsets too like a mobile intercom. Signaling is time division multiplex digital, so no interchannel interference. Cost of a handset, about 150GBP; the base station is another 150GBP. If you use the handset in mobile mode, you need to subscribe with one of the four telepoint operators. Peter Thurston