White Paper: Cellular Direct Connect AT&T Paradyne 8545 126th Ave N. Largo, Fl 34635 800-482-3333 (or 813-530-8623) How do I connect a modem to a cellular phone? ============================================= There are two primary ways of connecting a modem to a cellular phone: 1. RJ11 Adapter Box 2. Direct Connect Cable Each of these is described below. 1. RJ11 Adapter Box Modems are designed to interface to the PSTN (Public Switched Telephone Network -- the "dial" network.) As such, they require call progress and signaling information from the telephone company Central Office (CO). Examples of these signals are: off-hook indication to the CO, dial tone from the CO, touch tones to the CO, etc. Cellular phones do not provide this signaling information required by the modem. They provide their own proprietary interface, which has been designed for cellular phone accessories (hands-free kits, etc.) A special adapter box can be placed between the modem and the phone. This box is called an "RJ11 Adapter Box". (The name comes from the "RJ11" connector that the modem plugs into for PSTN operation.) This RJ11 Adapter Box provides the necessary conversion between the signals required by the modem and the signals required by the cellular phone. 2. Direct Connect Cable RJ11 Adapter Boxes are necessary because regular dial modems were never meant to be connected to cellular phones. Conversely, a modem with Direct Connect is designed from the start to interface to the cellular phone -- all the necessary mechanical, electrical, and software "hooks" are included in the modem. Thus, the interface between the modem and the phone is nothing more than a simple cable (the "Direct Connect Cable"). Since users will also want to connect to the PSTN, Direct Connect modems usually have two connectors: 1. A PSTN connector for the dial network 2. A Direct Connect connector for interfacing to the cellular phone What are the advantages of Direct Connect? ========================================== Direct Connect offers numerous advantages over RJ11 Adapters: 1. Less Clutter A Direct Connect Cable is much less cumbersome than the extra box and cables required for RJ11 Adapter Boxes. When you are mobile, the less equipment you have to carry the better. 2. Less Cost RJ11 Adapter Boxes usually cost over $300. This is typically more than the price of the modem or the phone! Direct Connect Cables for AT&T Paradyne modems are usually priced around $50 (slightly more for certain phones). 3. No batteries RJ11 Adapter Boxes require a battery. (RJ11 Adapter Boxes for 3-W phones usually are powered from the phone.) This battery usually has a short life -- and is prone to fail at the worst time! A Direct Connect Cable requires no batteries. 4. Better Performance Direct Connect offers a "cleaner" audio interface to the phone -- higher speeds and greater connection reliability is obtained. Where do I connect to the phone? ================================ Handheld phones usually have a connector on the bottom of the phone. Three watt phones (mobile and transportable) require a "T" connector that allows the handset and modem to plug together into the transceiver. What about PCMCIA vs. Pocket Modems? ==================================== AT&T Paradyne offers Direct Connect with its KeepInTouch PCMCIA modem. A PCMCIA modem coupled with a Direct Connect Cable is the best alternative for mobility. Compare this to a Pocket Modem with an RJ11 Adapter Box: 1. Clutter PCMCIA Modem + Direct Connect Cable vs. Pocket Modem + RS232 cable + Pocket Modem charger + RJ11 Adapter Box + RJ11 Adapter Box Charger + Extra cables between the pieces 2. Batteries Try maintaining four devices with batteries -- the Computer, the Cellular Phone, the RJ11 Adapter Box, and the Pocket Modem -- long enough to make a cellular call! What phones are supported by AT&T Paradyne? =========================================== While several other modem manufacturers support a limited number of phones, the AT&T Paradyne KeepInTouch card supports the widest variety of phones in the industry. The following is the current list of phones supported by the KeepInTouch card. This list is constantly being updated as new phones are added -- call AT&T Paradyne at 800-482-3333 for the latest list. AT&T 3610, 3710, 3730, 3760, 3830, 3850, 6650 Nokia 121, PT128, 232, 2120 Technophone 415, 515, 815 NEC P110, P120, P180, "TalkTime" series Many phones are "private labeled" with the name of the Cellular Service Provider. If you have a phone labeled as such, contact your Cellular Service Provider to see if your phone is on this list.