Wireless Data
There are three basic services offered by wireless data systems: circuit switched data, packet switched data and messaging.
Circuit switched data is a bearer service as it only transports the user’s data between points. When sending data through a circuit switched connection, the user regularly pays a standard per-minute charge for the amount of time that the connection is maintained regardless of how much data is sent through the channel.
It usually takes approximately 10 to 20 seconds to establish a circuit switched connection on a wireless network. This is due to the processing of dialed digits through the telephone network and the amount of time the modem requires to establish which communication language will be used (called training time). The user ordinarily pays for this setup time even if they only have a very small amount of information to send (such as an email message). Once a connection is established on a circuit switched connection, data transfer rates generally range from 9600 bps up to 28,800 bps.
Packet switched data is also a bearer type of service as it only transports the users data between points. When sending packets of data through the network, the user normally pays only for the amount of data or number of packets that they send.
Unlike circuit switched data, the connection time for packets is ordinarily under 1 second (some systems may be below 150 msec) and the user does not pay for this setup time. The typical price for packet data transmission ranges from approximately 4 cents to $1 per kilobyte. A one-time activation fee is as a rule required along with a minimum monthly fee. The usage amount is normally applied to the monthly fee.
Several wireless data service providers in the United States now offer service based on application and number of units. This results in different price plans that can vary from $15-25 per month per unit with some systems offering a flat fee for a fixed or unlimited amount data transmission. The trend is to move away from the per packet charge.
Figure 1 shows a typical wireless packet data rate plan. This table shows that there is usually a monthly recurring fee that provides the user with a monthly amount of data. If the customer uses the maximum data allocation, an additional fee per kilobyte or megabye of data is charge.
Wireless messaging is a teleservice as it processes the user data. Wireless messaging services include store, forward, and Internet connectivity. Typically wireless messaging is combined (bundled) with wireless data service (such as packet data).
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