3. PARALLEL IMPORTED CELLPHONES
Cellphones are a good example of products sold worldwide with the same brand and model name, but with different technical characteristics for different markets. Because of such technical differences, overseas cellphones may not be entirely compatible with the New Zealand Telecom cellular phone network.
Our network, like other AMPS networks, is based on the North American EIA/TIA standards. These standards provide for up to 1021 channels, but only 666 of these are available to Telecom. Telecom's AMPS spectrum is divided into two parts, the A band and the B band, each of 333 channels. It is common AMPS practice to use separate control channels for each band. However, unlike many overseas networks, Telecom uses B band control channels for the analogue traffic channels in both bands. Another problem is that the EIA/TIA standards provide numerous options for the implementation of services by network operators. The fact that any two products comply with these standards does not mean that the two products perform in the same way. This is especially the case with digital cellphones manufactured to specification IS 136, which provides for a very wide range of optional features and implementation methods.
The Telecom cellular phone network supports analogue cellphones (AMPS), three versions of digital or D-AMPS cellphone types, and the Cellular Digital Packet Data (CDPD) service. To do this, the Telecom network uses a unique set of control channel signalling messages and channelling assignments. In particular, while analogue control channels are located in the dedicated B band control channel set (channel 334 to 355, inclusive), digital control channels are generally allocated in upper limits of the B band from channel 627 to channel 666. This is not the case in most overseas networks.
In addition to signalling messages and channel assignments, the Telecom network has other features unique to New Zealand. For example, we use "111" for emergency services. Also, there is no single world standard for the use of * and # keys and these may be used differently in equipment designed for other networks.
Some overseas cellphones may not only be incompatible with these signalling arrangements, but actually be such that they can cause interference to Telecom's network and existing customers.
Because cellphone verification testing is particularly complex and expensive, Telecom's approach is to rely on the original tests carried out by the manufacturer and those carried out for the US Federal Communications Commission. We then only have to test for network compatibility. Almost all AMPS cellphones have an FCC Identifier on the product label as confirmation that radio frequency emissions and
basic operation proved satisfactory. Telecom's obligations to Government under its spectrum management rights are more strict than those of the FCC. We do not usually re-test the product, but we do review the original FCC test data to determine the margins by which the product passed their published requirements.
Knowing that the FCC has verified the basic radio requirements, Telecom engineering staff can focus on network compatibility issues, particularly those related to our unique uses of the cellular band. This saves repeating tests previously carried out in other countries, ensures minimum costs and delays for the Telepermit applicant, while still ensuring the product will perform correctly. However, this procedure can only be effective where we have the manufacturer's written assurance that the software has been specifically designed to match the Telecom network.
This assurance is not available where product was originally designed for an overseas network and we may have to repeat some or all of the FCC testing in such cases.
It is important to note that the software design for New Zealand, the original test reports and other product information are all regarded as the intellectual property of the manufacturer, who authorises the official New Zealand agent to make use of them in applying for a Telepermit. Telecom is NOT at liberty to make use of any such information provided by the authorised agent when testing parallel imports. In view of this, the parallel importer must either ensure that this information is supplied with any cellular products submitted for Telepermit, or provide a letter from the manufacturer or official New Zealand agent authorising the parallel importer to use the information supplied to Telecom with the successful Telepermit application.
Where cellphones have been made for overseas markets, other quite different changes may have been made to the original FCC-approved product, but our reduced test programme may not reveal them. It is thus important that we are advised of the original market for which imported cellphones were produced. We also need to be provided with the programming information necessary to actually test these cellphones. This information is usually held only by the manufacturer and the authorised agent.
In line with its neutral approach towards parallel importing, Telecom requires that each Telepermit applicant for cellular terminal equipment provides the following:-
a. two samples of each type of device (including any variants),
b. a copy of the FCC test report and approval certificate,
c. manufacturer's attestation that the cellphone meets the relevant specification
d. software version (or versions, where more than one is involved) and all necessary programming and testing codes,
CTIA report (where available),
f. details of the quality assurance system used to manufacture the products, and
g. details of the after-sales support arrangements for the New Zealand market.
Where "b" can not be made available, it will be necessary for repeat testing to be carried out in this country at the applicant's expense. This cannot be done without the test codes in "d", so these are essential.
A separate, but important issue, is electrical safety. Battery chargers do not connect to the Telecom network, so their compliance is not of direct concern to Telecom. Nevertheless, power packs and battery chargers are required to be safe under the New Zealand Electricity regulations. Prospective purchasers should thus ensure that they have evidence of compliance with the appropriate electrical safety standard, such as AS/NZS 3108.
SECOND-HAND AND REFURBISHED CELLPHONES
The short marketing lives of cellphone designs, reducing prices and continuing improvements in design make for regular replacement of cellphones by many customers. In addition, the rapid development of digital cellular services, the recent turmoil in the Asian markets, and the phasing out of AMPS services in Australia, all contribute to large quantities of second-hand cellphones on the world market. These are often refurbished by third parties (not the original manufacturer) and there is the risk that a number of national variants or cellphones with different versions of the operating software will be mixed together in a single batch of refurbished units. This is even more of a risk where the refurbisher has replaced the plastic case and the original manufacturer's label is no longer attached. Also, of course, there is no assurance that a second batch of similar phones is actually identical to the first. Any testing arrangements to ensure network compatibility are thus made far more difficult.
Telecom requires that the importers of refurbished cellphones provide some assurance that all units of a batch are of a known origin and that this origin is common to all. It may be necessary to carry out separate tests where the range of ESN's (the electronic serial numbers set by the original manufacturer) indicates that there could be different designs within the batch.
NEW ZEALAND LEGISLATION
There are several aspects of New Zealand law that impact on parallel importers. An importer is generally regarded as the "manufacturer" and is thus responsible for ensuring that the product complies with all regulatory requirements. These include, of course, safety and radio interference compliance.
Consumer protection legislation, namely the Fair Trading Act and Consumer Guarantees Act, require that no false or misleading statements are made about any goods, and that reasonable provisions are made for ongoing servicing or replacement of the goods, should they fail in some way. Above all, the supplier is required to ensure that all goods are fit for their intended purpose.
It is important that an importer takes these issues into account when considering the purchase of products, especially if they are refurbished items from overseas sources. Whether or not the refurbisher is recognised or accredited by the original manufacturer is another significant point. A lot more confidence can be placed on a supplier that is formally recognised by the original manufacturer as having an accepted quality assurance system and the capability of properly setting up cellphone software for the intended network.
It is strongly recommended that all prospective parallel importers of cellphones carefully check out any products offered to them. It is best to ensure that they comply with Telepermit requirements and will meet all regulatory requirements before any commitment is made to purchase the products in question.
4. NEW TESTING PROCEDURES FOR NETWORK INTERCONNECTION
Network interconnection testing to confirm compliance with PTC 331, Telecom's ITU No 7 signalling specification, has often resulted in problems with scheduling our model exchange (the NEAX 61E exchange reserved especially for software and interconnection testing). Telecom uses the model for its own exchange software evaluation and, frequently, several other network operators wish to use it at about the same time. Due to this limited availability, test sessions have had to be booked some months ahead.
Despite this, we often find that a network operator has been somewhat optimistic and that there is no switch in the country when the test period is due to start, or that compliance problems arise right from the start of model exchange testing.
For network interconnection testing, the practice to date has been for the network operator to submit a statement claiming compliance with the specification. This is known as "Stage 1". This compliance statement has generally been accepted at face value. Stage 2 is a series of actual tests using Telecom's model exchange. Once compliance has been confirmed using the model, the new network is actually connected to the Telecom network for final calling and billing tests covering the full range of call types offered by the network operator concerned. This is known as Stage 3. Commercial service can commence once this has been completed.
Stage 2 testing currently takes about four weeks, but only if the other network operator's system is fully compliant with the specification. Most are not, so testing frequently takes place in a series of sessions interrupted for software modifications. As a result, the testing period may extend to months rather than weeks, depending on the resources available to overcome any problems. Other network operators' schedules can then be disrupted.
Telecom attempted to overcome these scheduling problems in 1998 by requiring each new network operator to carry out its own preliminary off-line testing using a leased test system directly equivalent to that used by Telecom. In this way, the network operator could ensure that their network equipment had a reasonably high level of compliance. The results were used to prepare the Stage 1 compliance statement. Given satisfactory pre-model test results, it was expected that actual model testing would be straightforward, with no interruptions. Bookings for the model exchange were accepted only after these
pre-tests had been completed, reducing the booking ahead period and overcoming some of the scheduling problems described above. Unfortunately, pre-testing by the network operator has not proved very successful, largely due to the complexity of these tests, the lack of detailed understanding of the protocols, and limited familiarity with both the tester and the new equipment concerned.
To overcome these problems, Telecom is now introducing a procedure similar to that used for CPE testing. Two independent testing organisations have so far offered their services to carry out interconnect testing for network operators. These are Nichecom Ltd and TSSC Ltd, both in Wellington. It is likely that other parties with the necessary expertise and access to the specialised test equipment may also wish to carry out testing for network operators and Telecom will consider further applications. Telecom requires all such parties to undertake a specialised training course in order to gain formal accreditation for this work before they offer their services to network operators.
The entry of independent testing services will not only provide choice for network operators, but also ensure that there is a good chance of testing facilities being available at all times. All test facilities accredited by Telecom for this class of testing will be able to provide skilled staff to undertake the test programme. They will work with the network operator or its equipment supplier to complete a preliminary test report, roughly equivalent to the original Stage 1 and about 75% of Stage 2. Once this report shows that tests have been completed correctly, Telecom's final Stage 2 model testing is expected to reduce to about one week, with little or no risk of interruption. This should free up the model exchange to such an extent that we are able to schedule testing at relatively short notice.
Network operators should note that we are also changing the model exchange booking arrangements. To avoid confusion over timings and the need for constant rescheduling due to unplanned extended testing, we will now accept a firm booking for model exchange testing only after a satisfactory test report has been submitted from an accredited test facility. Network operators may "pencil in" a booking once their equipment has arrived and they have commenced the preliminary tests, but this will not be confirmed until the test report has been submitted. In general, we expect the final model testing to be scheduled within 2-3 weeks of satisfactorily completing the pre-tests.
These changes in procedure are expected to speed up the overall testing process by having several separate "streams" available for testing, each with expertise available to assist a new network operator or equipment supplier. The cost of hiring Telecom's model exchange for what may otherwise have proved to be long periods will be avoided. Above all, it will greatly reduce the risk of Telecom's model exchange being a bottleneck due to unscheduled extended test periods.
The new procedure is being introduced as quickly as possible and Telecom staff are planning to run a training course during the May-June period. This will be the basis for accrediting the independent test services. Telecom will not charge for the training, provided that the participants' companies certify that they are willing to offer commercial services as soon as they have been accredited by Telecom. When one or more companies has been accredited, network operators requiring PTC 331 testing will be advised to approach these companies to determine charges and availability to best suit each network operator's overall project timing. The equipment used is reasonably portable, so testing will probably be able to be carried out at the network operator's site, where necessary.
Any additional parties wishing to undertake independent PTC 331 testing on a commercial basis are invited to contact Telecom's James Teoh by telephone on (04) 802 6654 or by fax on (04) 802 6693.
5. NETWORK RINGING DEVELOPMENTS
Telecom's customer line provision technology is progressively moving from copper cable to derived systems of various types. These changes are having some side effects on ringing characteristics in that derived systems are often remote from the exchange and associated with shorter customer lines. In some cases, they may actually be located at the customer's premises.
As a result, the "traditional" 80 V rms ringing generators in the local exchange are no longer being connected directly to many customers' lines. Instead, the relatively low powered ringers equipped in individual derived access systems are used. With the shorter lines and different source impedance, these derived system ringers still deliver the 107 V peak-peak used in our PTC 200 ringing tests. However, there is no latitude to deal with any ringing and answering devices which need higher voltages to operate correctly.
Unfortunately, we have little choice but to accept these ringing changes, as the derived systems are manufactured to industry standards and this is a worldwide trend.
As a result of these developments, our Ringer Number tests will need to be revised to ensure that all CPE ringers and automatic answering devices will operate reliably with the 107 V peak-peak test voltage. Our Ringer Sensitivity test is currently used to derive the Ringing Number (RN) where the ringer or auto answer circuitry needs a voltage higher than 107 V p-p. This provision has been rarely used in practice, but with derived systems, any device needing the higher voltage may not operate at all!
Prospective purchasers will not know whether their lines are subject to reduced ringing voltage, so there would be problems for retailers should customers return low sensitivity products as "faulty". Similarly, any network changes leading to reduced ringing would affect insensitive types of CPE. The only practicable solution is that ALL analogue devices submitted for Telepermit shall operate reliably with no more than 107 V peak-peak. The Ringing Number will thus be directly equivalent to the measured Ringer Load value, without any qualification for sensitivity.
CPE suppliers should regard the above as warning of this new requirement for reliable operation of ringing or auto answering devices with 107 V peak to peak ringing signals. A review of test reports indicates that very few items of CPE will be affected. On the other hand, any device which fails to ring when lines are converted from "copper" to derived systems, may cause problems for users. In the circumstances, this requirement will come into force on 1 August 1999. PTC 200 will be amended accordingly.
DOUG BURRUS
Manager
Access Standards
