These business functions are best handled by specialized business computers that are programmed specifically to provide these functions. In order to coordinate the paging terminal database with the customer database that resides on the business computer, paging terminals normally provide a data port that is capable of executing a protocol that allows for the transfer of customer database information into and out of the paging terminal. Business computers implement this protocol so that they may program new customer accounts, put delinquent accounts on hold, delete terminated accounts, collect billing information and verify that customers who are not accounted for in the billing computer have not been manually added to the paging terminal.
In most cases, this special data port also can be used to forward a radio page request. This allows the business computer or other computer system to initiate paging. Many specialized applications have been developed on external computer equipment that gather information and then broadcast this data by feeding it through the computer interface ports of the paging terminal. Although many of these applications can use the TAP or TNPP ports to forward page requests, certain applications require access to the paging terminal customer database in addition to generating page requests.
Computer interface protocols are specific to each manufacturer's paging terminal equipment. In general, though, each performs similar functions in similar ways. These ports normally operate in a command/response mode, meaning that the host or billing computer will initiate a command and await a response. The commands normally are oriented to read customer data, write customer data or alert a pager. Some protocols require that the entire customer record be read or written at one time, while other protocols allow one field, a set of fields or many individual fields to be read or written at a time. Those host protocols that allow operations in a networking environment may allow the host computer to specify a network address of the paging terminal that contains the specific information that is being read or written.
Host computer protocols are fairly straightforward, issuing one request and expecting one response; they normally do not overlap multiple requests at a time.
To generalize the formats of billing computer interface ports on paging terminals, the following is typical of the protocols used. Not all of the steps or features exist on some paging terminals:
Host or Billing Computer | Paging Terminal |
<Asks for attention> | <Ready> |
<Network or local address is specified> | <Address Accepted> |
<Request read of a record, individual field, or a set of fields> | <Returns data> |
<Requests update of a record, individual field, or a set of fields> | <Updated Accepted> |
<Requests page alert of a tone only, numeric or alphanumeric pager> | <Page Accepted> |