3. CALLER DISPLAY CHANGES FOR PAYPHONE ORIGINATED CALLS
Telecom currently uses Single Data Message Format (SDMF) to send both the A (Calling) number and the date/time for its analogue line Caller Display service. In addition, the special alpha codes “O” and “P” are sent to indicate “out of area” and “private” (withheld numbers). These codes may be sent in place of the calling number.
Telecom does not disclose the directory numbers of its public payphones for security reasons, so calls originated from these payphones have always been included in the “P” category.
Telecom is introducing an enhancement to its Caller Display service that will specifically indicate calls that are originated from Telecom’s public telephones. To do this, the full word “Payphone” will be included in the caller display information sent from the network.
Testing with a range of existing types of caller display-enabled CPE has shown that reliable indication of payphone-originated calls will have to be sent using Multiple Data Message Format (MDMF). We will be using a four-digit “dummy number” (0101) in the number field and “Payphone” in the name field.
Calls originated from sources other than Telecom payphones will continue to use SDMF (thereby causing no confusion to customers or to their CPE).
PTC 200, clause 11.4.4 requires that all display-capable CPE shall be MDMF-capable, which is the usual overseas practice for number and date/time anyway. As such, we are not expecting any in-service CPE to be “confused” by the change. A very low percentage of calls originate from payphones these days in any case.
Any display-capable CPE that, for some reason, does not fully comply with PTC 200, clause 11.4.4, may not display “Payphone” and show only the number “0101”. Either of these caller display messages will indicate to the called party that the call originated from a Telecom public payphone.
As our tests did not cover ALL types of CPE offering a “Caller Display” feature currently in service, suppliers of such CPE are advised to check with their manufacturers to confirm that their equipment is compatible with this change.
4. PTC 213: REQUIREMENTS FOR PAY TELEPHONES
PTC 213 was originally published in 1990, but has had relatively little application since that time. Nevertheless, there is still some demand for both public and private pay telephones and recent Telepermit enquiries revealed the need to fully revise this specification before it was made available “on-line” along with most of our other PTC Specifications
The current draft may be subject to further amendment after receipt of industry comments, but it provides a lot of information on payphone-specific issues, such as security and coin validation. In particular, of course, it is important that payphones connected to the Telecom network can determine call charges without the need for periodic meter pulses to be sent from the local telephone exchange.
In addition to the payphone-specific aspects in PTC 213, the technical requirements of PTC 200 apply to all payphones (and their associated data modems, where applicable) which are connected to Telecom’s analogue lines
The draft for public comment in .pdf format is now available on the Telepermit website. See http://www.telepermit.co.nz/PtcSpecs.html . Comments and suggestions are welcomed (as are further questions on payphone-related topics that may not have been covered).
5. TELECOMMUNICATIONS RELAY SERVICE
A decision on introducing this service and an announcement of the chosen contractor are expected shortly. As explained in Newsletter No. 147, we expect to cover the associated CPE in a new PTC-series, even if acoustic couplers are used and there is no direct electrical connection to the Telecom network.
There are some concerns over whether all CPE items will be compatible with the Telecom network and with the new relay service equipment, especially if any proprietary coding systems are used.
More on this subject can be expected in future Newsletters.
Doug Burrus
Manager
Access Standards
