TELECOM ACCESS STANDARDS NEWSLETTER NO. 139 April 2003 CONTENTS 1. WITHDRAWAL OF SUPPORT FOR DECADIC SIGNALLING 2. PTC TESTING WITH INTENDED POWER SUPPLIES 3. "GENERAL PURPOSE" PABX TELEPHONES 4. PTC 256: TELEPERMITS FOR CDMA TERMINAL EQUIPMENT 5. PTC 220: PRIVATE NETWORKS - DRAFT FOR PUBLIC COMMENT 6. "111" EMERGENCY SERVICE CALLS 7. INCREASED CHARGES FOR TELEPERMIT APPLICATION PROCESSING RETURN TO MAIN INDEX 1. WITHDRAWAL OF SUPPORT FOR DECADIC SIGNALLING As has been mentioned from time to time in these Newsletters over the past ten years or so, Telecom is not intending to support decadic (dial pulse) signalling in the future. Its latest generation of access transmission systems are the first network items that set this restriction. The same will apply to other parts of its "Next Generation Network" equipment as and when they are installed. The last decadic signalling telephone was Telepermitted in 1996 and even this was an exception at that time. PTC 200 continues to define requirements for decadic signalling CPE, but it is now announced, as a matter of formal record, that no further CPE with decadic-only signalling will be granted Telepermit after August 31. This complies with Telecom's undertaking to give at least 3 months notice of any significant change in the network interface. In line with our usual practice, overseas-sourced products offering both DTMF and "international" (as distinct from our "reverse ") decadic signalling will be granted Telepermit on condition that the product uses only DTMF when connected to the Telecom network. This change will have no impact on product sales, but will progressively impact on customers as our network is up-dated. 2. PTC TESTING WITH INTENDED POWER SUPPLIES There have been several cases recently where products have either caused noise to other CPE connected on the same line, or failed their "out of band" noise tests due to their own power supply units. This seems to be related to the wider use of small switched mode power supplies operating at high frequencies. To avoid the first situation, our accredited testing laboratories are asked to ensure that any products are tested for Telepermit purposes while they are powered with the actual power supply that is intended to be provided with all such products offered for sale on the New Zealand market. It is understood that some labs simply connect a product to their laboratory power supplies, as a matter of course. As a result, these noise problems may not be apparent during testing, but do arise in actual service and cause some concern to the customers involved. In view of the out of band noise problem, any change of power supply type needs to be treated with some caution, especially where a simple transformer/rectifier power supply is replaced with a switched mode unit. Even with the former, there is a risk that unbalance to earth will affect the product's performance. In such cases, the product should be re-tested to ensure that it still complies with out of band noise (PTC 200, clause 4.3) and impedance balance about earth (PTC 200, clause 4.8). 3. "GENERAL PURPOSE" PABX TELEPHONES The question of Telepermits for "general purpose" PABX telephone sets was raised in Newsletter No. 138. Further enquiries revealed that these were not, after all, replacements for the truly proprietary telephones used on specific PABX systems. They provide a number of DIP switches for configuring to a particular PABX, but these are only controlling such general aspects as Timed Break Recall durations and varying types of Message Waiting indication. In effect, they are standard PTC 200 telephones (not "proprietary sets" in the sense that they are using special signalling or transmission interfaces) with switching to match the analogue port interfaces of the PABX systems concerned. Since such telephones can readily be connected to the PSTN, testing to PTC 200 in the same way as any other analogue telephone is quite appropriate and they will be granted Telepermits in the PTC 202-series. Because incorrect settings of the various switches can upset the PSTN compatibility of these telephones when they are directly connected (eg, wrong TBR setting) an additional condition for Telepermitting such products is that the telephone set itself shall bear a label indicating the correct setting of the switches for PSTN connection. It is recommended that the same label gives a brief instruction to "Check the User Manual for specific PABX settings". To avoid confusion to prospective purchasers, it is also important that any references to "Message Waiting" indicators in sales literature clearly explains that this does not apply to direct PSTN connection. 4. PTC 256: TELEPERMITS FOR CDMA TERMINAL EQUIPMENT Telecom's "027" Code Division Multiple Access (CDMA) network is now well-established with 300 000 customers connected. So far, the handset market has been supplied largely by companies working in conjunction with Telecom Mobile Ltd, but the stage has now been reached where it should be practicable to invite other suppliers to offer suitable products for this network. To get such arrangements under way, Specification PTC 256 is now published on our website as a "Draft for Public Comment". This is essentially an "overview document" explaining the assessment process that has been set up. As was done with AMPS and D-AMPS handsets for our 025 network, heavy reliance is placed on products having previously been tested overseas. Thus prospective suppliers are asked to submit reports demonstrating compliance with the appropriate EIA/TIA industry standards, FCC requirements, Specific Absorption Ratio (SAR) tests, etc. For SAR, compliance with NZS 2772 is the prerequisite. While every CDMA network is expected to comply with the primary standards published by EIA/TIA, each national network does have its own specific functionality and features, which are often implemented quite differently. For example, in Telecom's case, the 027 network has many features closely tailored to integrate with PSTN and Xtra services. As a result, it is very difficult, if not impossible, for an overseas supplier to confirm remotely that a handset is fully compatible with the Telecom 027 network. Full confirmation of the many network supported features and functions requires connection to the live network under typical operating conditions. PTC 256 explains that such tests are carried out by Telecom Mobile's own staff as a means of re-assuring both Telecom and the local supplier that the features offered by a product do actually work as claimed. By having our own staff customise this work according to the features of each individual product, it can be combined with the usual Telepermit assessment process. Needless to say, the vast range of features offered on a modern CDMA handset mean that assessment of network compatibility is quite an involved process and our charges will have to reflect this. To assist prospective suppliers, Telecom will offer an optional "preliminary assessment service" at NZ$500, plus GST, per product type. This will evaluate the documentation provided by the supplier and carry out a brief evaluation to reveal any major incompatibilities so that the supplier can be given an indication of whether it seems worth proceeding to a full evaluation. Note that passing this initial assessment does not necessarily mean that the product will be eligible for a Telepermit, as other issues may come to light during a full evaluation. Suppliers can, if they wish, request a full assessment of their product. The charge for this work has been set at NZ$2000, plus GST, and successful assessment under this process will result in the grant of a Telepermit. Nevertheless, suppliers should allow for the possibility that software changes may be necessary to actually meet Telecom network compatibility requirements. In fact, this need has arisen fairly frequently with product already Telepermitted. Also, should a supplier have to go through several iterations of software, such that Telecom incurs considerably more work than would normally be required, an additional re-test fee may have to be levied. Further information is given in PTC 256, which can be accessed free of charge on our website at www.telepermit.co.nz/ptc256.pdf. A companion document, "CDMA Device Default PRI" is published with PTC 256. This provides network specific information needed by handset manufacturers. An Telepermit Application From for CDMA Mobile Equipment is also published on our website. This is to be completed by the applicant to provide product and contact details and a summary of the features and functions offered by the equipment concerned. 5. PTC 220: PRIVATE NETWORKS - DRAFT FOR PUBLIC COMMENT The Draft for Public Comment of PTC 220, covering private network performance requirements, including VoIP operations, is now available on our website. For the full text, see http://www.telepermit.co.nz/ptc220.pdf This document was previously circulated to several of our testing laboratories for comment. Unfortunately, most do not yet have the equipment needed to fully test to this specification, but it will provide equipment suppliers with a better idea of what we are seeking to achieve in order to avoid degradation of PSTN service performance for customers in general. The requirements are based on compliance with Telecom's overall Transmission Plan, which is being revised to recognise the impact of growing use of Voice over IP in private networks and, of course, the proposed introduction VoIP within the core PSTN. The overall plan and the requirements of PTC 220 align with the ITU-T E Model, which was explained in Newsletters 129, 131, 134 and 135. 6. "111" EMERGENCY SERVICE CALLS A case recently came to notice where a toll barring system had been implemented in some new customer equipment and calls to our Emergency Service had been barred. This is possibly the first such case since we commenced the Telepermit system in 1987. Unlike Australia's ACA, Telecom does not mandate the ability to make emergency calls from every telephone and does not require a test laboratory to confirm that such calls can be made. Similarly, toll barring functions are regarded as "marketing features" and not part of PTC 200 testing. Nevertheless, we strongly recommend that "111" calls are not barred under any circumstance. Because toll barring set-up is often site specific and very flexible, it is not intended that test labs should endeavour to assess such systems. Instead, it is recommended that Telepermit applicants confirm emergency calling capability by thoroughly checking the product documentation. Clause 6.11 of PTC 200 makes allowance for mains-powered telephones, which may be incapable of calling any numbers under power fail conditions. It is proposed that if there are circumstances under which there is no reasonable alternative to barring emergency calls under normal operating conditions, then the telephone itself shall bear a simple warning notice to clearly indicate that such calls cannot be made. A related issue is the provision of "one touch" emergency call buttons on telephones. "111" is a fairly easy number to remember and not difficult to dial. Despite this, some telephones, cellphones in particular, provide a one touch button for emergency calls. These are the cause of thousands of inadvertent emergency calls every month, as people sit on cellphones in their pockets or press something against a cellphone inside a bag or case. Such calls provide a further complication in that the emergency service operator answers the call, but no one speaks. This causes concern that it might just possibly be a genuine call for help from someone who has been incapacitated. A "one button" scheme also has the drawback when used on a PABX in that it is still necessary to dial the appropriate trunk access prefix before pressing the emergency button unless it has been specifically programmed for that PABX. All in all, we are not enthusiastic about the provision of "one touch" buttons for "111" calls. 7. INCREASED CHARGES FOR TELEPERMIT APPLICATION PROCESSING A reminder to prospective Telepermit applicants that our charges for Telepermit processing will increase by a nominal 16% across the board from 1 July 2003. Our revised charging structure, exclusive of GST, was published in Newsletter No. 138. Telepermit applications received before 1 July 2003 will be processed at the current charge, but only if they have been sent with all the necessary submission information by that date. As stated earlier, we will continue to provide our usual advisory service to Telepermit applicants at no cost, as we are happy to assist suppliers to meet our requirements in what ever way we can. DOUG BURRUS Manager Access Standards