VisorPhone Drops to $50

I was lucky, and found one used.

But this is DEFINITELY an amazing module, and well worth the price. Depending on how much it is without an activation, it might be worth it for current GSM subscribers to look into..

http://home.foni.net/~mohnhaupt/pilot/GPRStp260.htm

It works really good, although the prices are a little high.

TDMA (Time Division Multiple Access) -- A tech term regarding how many users can share the limited physical resources (such like the frequency..). Each user is assigned a fixed time slot in order to share the medium and gain the access to the service. Each user has to transmit and receive in that particular time window assigned to him and there will be some time period wasted at the beginning and the end of thet window. It is more difficult to gain higher speed with this type of access scheme compared to CDMA. Many cellular standards adopt this type of access method including GSM and US own TDMA standard (called AMPS (Advanced Mobile Phone Service which is an analog system). And later on there is a digital system called IS-54).

CDMA (Code Division Multiple Access) -- A tech term regarding how many users can share the limited physical resources (such like the frequency..). Each user is assigned a special code to share the medium and gain access to the service. Everybody can transmit and receive at the same time, they can be seperated by the special code assigned to them. Therefore there is no the wasted time period as TDMA. However, there are some tech problems with this type of access method. The product is more expensive to make but higher speed is more possible at the cost of shorter battery life & more expensive. Qualcomm CDMA (IS-95) and the 3G are using CDMA.

GPRS (General Packet Radio Service) -- The data service enhancement of GSM. GPRS is the name not a tech term either. GSM is mainly for voice, and 3G is mainly for data, and there is a transition from GSM to 3G, GPRS (and later on a faster EDGE) will be the data service enhancement based on GSM to fill in the gap before 3G can be actually accepted. The good thing is that since it is based on the existing GSM, the cost is a lot less than the brand new 3G. Since GPRS and EDGE are basically GSM based, they are also TDMA.

3G (Third Generation Mobile Network) -- The next generation cellular network targeting at data service ith a much higher trnasfer speed. 3G is using CDMA as the medium sharing method (so each user can transmit and receive at the same time but still can be seperated by the special code assigned to each user).

IEEE 802.11b (or Wi-Fi) -- The name of the standard for wireless local area network (WLAN). It is mainly for sophisticated networking and can be a complement to the wired eithernet found in many office and now home. It is much higher speed, the range is longer and the performance is better but more expensive.

Bluetooth -- The name for a short range wireless connectivity mainly used for cable replacement. The speed is slow and the range is shorter and the performance is not as good as Wireless LAN but it is supposed to be much cheaper.

CDPD (Cellular Digital Packet Data) -- The name of the data service in US-TDMA (AMPS). Many wireless service providers are using this to provide wireless DATA such like Omnisky (if I am correct). The Ricochet network is their own proprietary system.

GPS (Global Positioning System) -- The name of a positioning system using the signals transmitted by many sattelites (at least three) to calculate the position and altitude.

PCS (Personal Communication Service) -- The name of a wireless service to provide a ubiquitous access.

.......

The CDMA Visor phone that should be out soon might be expected to have better coverage in the US.

Does anyone know about comparative internet access speeds for GSM & CDMA??

Thanks!

It is the nature of electronics to drop in price. Get used to it.

This is bad business.. we all lose when they devalue their own products.