Why This Equipment Won't Work For Data
Cellular interconnect equipment (ie: Dock-N-Talk equipment, XLink, Cell2Tell, etc.) are VOICE ONLY appliances. They work much like a hard-wired vehicle kit with the main difference is that you are using a conventional wired (analog) phone connected to this equipment instead of a separate mic and speaker as used with a vehicle kit. Both this equipment, and a vehicle kit, uses the VOICE circuits in the cell phone. These circuits and the "VoCoder" in the cell phone are designed for the narrow frequency range (3000 cps) of the human voice. These circuits convert the human voice to a series of "1's" and "0's", compresses this information, and sends it to the nearest cell site in data bursts of 7 milliseconds each. The cellular interconnect switch located miles away from the cell phone user converts these data bursts back into an analog signal that is then sent over conventional phone lines. The returning conversation is sent to the cell phone in these same data bursts. The cell phone's circuitry then converts them back into an analog sound. Because the transmission time of the data bursts is so small, we hear a continuous sound. In reality, the information is coming and going in quick bursts of information. Because of this type of transmission stream, broken up into digital bursts, data cannot be sent over a digital voice network.
Modems REQUIRE a continuous analog signal to work. Modems are found in fax machines, satellite TV units, computers, credit card terminals, alarm systems, DVR's, and TiVo units. The audible frequency range that a modem produces (300 to 18,000 cps) is considerably greater than the human voice (3000 cps). Modems cannot connect using a digital voice network because of the extremely limited audio frequency conversion from analog to digital within the phone's "VoCoder" and the data burst type of transmission. Also, modern modems operate up to 56kps. The old analog voice cellular system could only handle a maximum data speed of 9kps and was most reliable at the very slow speed of 2.4kps. No modern fax machine can operate that slow today and you usually can't even connect to the Internet below 14.4kps. You also have to use the "#" key when using some interconnect equipment as the last digit dialed. (The "#" key does the same function as the "Send" key on your cell phone.) This dialing string requirement also eliminates the use of this type of interconnect equipment because credit card readers, TiVo units, and satellite TV units are pre-programmed by the various services to dial only their phone number and these numbers cannot be altered by the user to add the "#" key. The user of cellular interconnect equipment will hear a "dial tone," but that is just for us humans and is not transmitted over the network.
A conventional ANALOG LAND LINE is required with fax machines, satellite TV units, computer modems, credit card terminals, alarm systems*, DVR's, TiVo,or any equipment that has a modem. Thus, you CANNOT use fax machines, satellite TV units, computer modems, credit card terminals, alarm systems*, DVR's, TiVo,or any equipment that has a modem with:
Internet or WiFi
Some VoIP (Vonage, Clearwire, and MagicJack will allow modem connections in most markets.)
Digital cell phone
Some mobile satellite services. Globalstar does offer both fax capability (requires a fax machine interface adapter starting at $849) and at a very low speed Internet connection speed.
*Some alarm systems are capable of sending a voice message instead of a data code. These alarm systems can use cellular interconnect equipment.
Most of the new cell phones on the market will allow connection to a carrier's special data network to send and receive data transmissions, often at high speeds (4G). If you want to send data over cell phone, you will need to purchase a data capable phone and the proper USB data interface cable (or a Bluetooth module for your computer if your cell phone has Bluetooth capability) that will allow you to connect the phone to ONLY a computer. This system use the DATA circuits in these new cell phones, not the voice circuits. This data application is also called "Tethering" by the cellular carriers. There is also an extra fee that you will usually have to pay to your cellular carrier to use their data service and for "Tethering."
If you want to send a fax using an Internet connection, either use "E-Fax" service from your computer or convert your fax to a .pdf file in your computer and send it as an e-mail attachment. In either case, you will be using a computer and not a fax machine.
FYI: The fax machine was actually invented in 1843, 30 years before the invention of the telephone, by Alexander Bain and was intended to replace the old "key" or Morse Code type transmission to send a document over a long distance almost instantly. The big change over the years is that it fax machines have gotten faster, better, and cheaper. But, the technology is basically the same as was used in 1843.