The Future of GSM Terminal Testing and Approvals

The European global system for mobile communication (GSM) terminal manufacturers are experiencing some changes in the testing and approval of their products. Beginning in April 2000, GSM terminals will be legally required to meet the new approach R&TTE Directive. Under this new directive, GSM terminal manufacturers no longer have to apply to notified bodies for product certification, and they can choose how they demonstrate compliance against harmonized standards. Many network operators are concerned with this new directive and have created a voluntary certification scheme for GSM terminal products. Another response to the R&TTE Directive has come from the notified body BABT, which has created a Certified for Network Connection scheme.

TTE Directive

Before April 2000, telecommunications equipment such as GSM mobile telephones were required to meet the Telecommunications Terminal Equipment (TTE) Directive (91/263/EEC). For a GSM product, the TTE Directive laid down common technical regulations (CTRs) as the means of defining the technical and regulatory essential requirements that terminal equipment was to satisfy before being granted type approval. The CTRs are based on TBRs (technical basis for regulations), which have been developed by ETSI (European Telecommunications Standards Institute). A notified body would issue a certificate against these CTRs. Compliance against the CTRs also allowed GSM manufacturers to place the cross hockey stick mark on their products.

The TBRs refer to the specific test requirements laid down in the ETSI document ETS 300 607-1, also referred to as GSM 11.10. The TBRs specified for phase 2 type approval used version 4 of GSM 11.10. The CTRs and TBRs for GSM terminals are 19 and 20 for GSM 900 phase 2 and 31 and 32 for GSM 1800 phase 2 and dual band.

The TTE Directive (as defined in Annexes 1–4) provided three common routes to compliance for GSM terminal manufacturers:

Under the TTE Directive, manufacturers are also obliged to meet other essential requirements, such as the EMC, Machinery, and Low Voltage Directives, in order to place the CE mark on their products.

Compliance testing, however, was not necessarily the whole story for GSM terminal manufacturers under this regime. Typically, manufacturers would perform many additional tests in-house and conduct extensive field trials. These field trials would often be conducted in areas of known weak signal strength or complex cell structures to determine and improve the real-world performance of handsets. Further testing also may have been required for products to be approved by specific network operators who conducted their own approval and acceptance testing.

 

R&TTE Directive

The R&TTE Directive appears to be one of the few pieces of legislation emanating from the European Commission in Brussels that is actually aimed at reducing both the financial burden and the time to market for manufacturers. It was formulated by the commission to facilitate free trade and free movement of goods and to speed up the emergence of new technologies throughout the European Union (EU) member states. Its key methodology is to harmonize the radio and telecommunications industry, simplify the conformity process, and reduce time for the introduction of new equipment.

Under the R&TTE Directive, GSM terminal equipment will have to satisfy the relevant harmonized standards to demonstrate compliance. The essential requirements will include electrical safety (73/23/EEC), electromagnetic compatibility (89/336/EEC), prevention of harm to both the network and to other users, and efficient use of the spectrum. (Some additional requirements are yet to be decided by the commission, including interworking, information protection, antifraud, emergency services, and features for the disabled.)

The directive defines conformity assessment procedures in a series of annexes, including:

Because a GSM terminal contains a transmitter and a receiver, manufacturers have the choice of using the conformity assessment procedures outlined in Annex III, IV, or V. Regardless of which route is used to demonstrate compliance, the manufacturer should test the product adequately and keep the necessary test records.

The Official Journal of the European Communities has listed a number of TBRs as harmonized standards for the R&TTE Directive. GSM terminal manufacturers are required to apply TBR 19 Edition 3 (October 1996) for GSM 900 terminals and TBR 31 Edition 2 (March 1998).

The R&TTE Directive will have two major implications for the GSM world: terminal manufacturers, by declaring compliance, will take on increased product liability, and network operators will get less protection from regulation.

 

Network Operators' Response

The GSM Association, which includes many network operators in its membership, was concerned with the risk of reduced regulation and initiated a voluntary certification scheme. It should be noted that this scheme is not mandatory, and network operators are free to purchase GSM terminals that have not been included in this scheme.

The current name for the scheme is the GSM Certification Forum (GCF), and it is expected to be fully operational by the time the R&TTE Directive has become law. Development of the GCF has been a cooperative effort of the GSM Association, representing the GSM network operator community, and GSM terminal manufacturers, to ensure the interoperability of GSM terminals worldwide.

The GCF provides a process for GSM terminal manufacturers for the test and verification of terminals against specified technical requirements. This certification is aimed at being globally recognized and is designed to avoid multiple testing as well as create cost efficiencies. This scheme does not provide any commercial or quality assurances from a terminal manufacturer to a customer. New requirements and tests may be incorporated into the forum once a standards authority has published them and validated test equipment is available. The GCF will likely evolve as GSM technology evolves so that it can encompass such future technologies as high-speed data and third-generation wireless air interface specifications.

The GSM certification program is a three-step process:

The creation and development of the GCF has proved to be a difficult process over the past couple years. There have been some particularly contentious issues between the network operators and terminal manufacturers. One such issue is that the GCF requirement for terminal manufacturers declares not only that the GSM product satisfies test requirements (GSM 11.10), but also that the product satisfies all related core specifications. This could cause difficulties for a terminal manufacturer because test cases do not exist to prove all of the core specifications.

Another issue has been to determine which version of GSM specification should be applied. As mentioned earlier, under the TTE Directive, version 4 (phase 2) of the specifications was used. Under the GCF scheme, terminals are required to meet version 5 (which includes phase 2+ features) in the short term, and then newer versions later in the year. This does not mean that terminal manufacturers must design in all the phase 2+ features, but it does mean that care should be taken where there have been changes made to existing phase 2 features. Manufacturers will have to ensure that their projects are in line with this progression of GSM versions.

By incrementing and using the newer versions of GSM specification, this should encourage the development and implementation of GSM phase 2+ features. The GCF scheme has highlighted a number of new and existing features that terminal manufacturers, test equipment manufacturers, and test laboratories should prepare for. Some of these include further short message service (SMS) phase 2 features, multislot phase 2+ features, and further supplementary service phase 2 features (e.g., multiparty, call forwarding, and call waiting).

The process of developing, issuing, and validating the test cases will continue in a fashion similar to today's process. Accredited laboratories will continue to validate test cases against the test specifications, GSM 11.10, and core specifications, before they can be categorized as applicable.

 

Regional and National Approval

For GSM terminal manufacturers who intend to sell products outside Europe, the requirements of national regulators need to be satisfied. This is an increasingly important consideration due to the dramatic growth of GSM and the adoption of its standard across the globe. Recent figures show that 215 million subscribers in 129 countries, 72 million of which are not in Europe, use GSM terminals.

This article will discuss a regional and a national approval scheme as examples. Much of the approval is based on ETSI specifications and European TBRs. It is unclear exactly what regional and national regulators will do, if anything, in response to the changes to the European requirements and whether they will adopt results from schemes such as the GSM Certification Forum.

In Australia, the Australian Communications Authority (ACA) uses Technical Standard 018 to assess compliance. The main requirement of a GSM terminal is to comply with the ETSI GSM standards, which manufacturers can demonstrate by applying the European TBRs. In addition to the TBRs, TS 018 states that the terminal shall also comply with the following requirements:

Manufacturers wishing to have products approved in North America are required to apply to the Cellular Telecommunications Industry Association (CTIA) for GSM-1900 Type Certification. The requirements specified by the CTIA and a PCS-specific review board include compliance with PCS 11.10, a modified version of the European standard GSM 11.10. Most of the differences are changes to the frequency bands.

One significant difference between the North American and European approval systems is that the North American system uses version 4 (phase 2) as a minimum requirement, and, in practice, uses higher versions of 11.10 for specific features and test requirements. North America already implements subscriber identity module (SIM) tool-kit and leak-tolerant earpiece testing as applicable test requirements.

A GSM 1900 terminal manufacturer may also apply for additional CTIA certification, which demonstrates compliance against such requirements as hearing aid compatibility and audioport accessibility.

 

Certification by Notified Bodies

The notified body BABT has launched a certification scheme for equipment called the Certified for Network Connection. This scheme will be based on the TTE practices and will provide a means for suppliers to ensure their customers and network operators of independent verification of compatibility with telecom networks. There will be a definitive, up-to-date, Web-based directory of all certified products.

The new scheme will operate from April 8, 2000. Products already certified by BABT under the TTE regulations will automatically qualify for inclusion in the directory. New certificates will be issued, and these will clearly state that the products satisfy the transitional provisions of the new R&TTE Directive. The scheme will offer enhanced Web-based reference resources for products that are newly certified after April 8.

 

Strategies for Manufacturers

All GSM manufacturers wishing to sell products into Europe must meet the R&TTE Directive's essential requirements. The R&TTE Directive has been a hot topic of conversation, and because harmonized standards or GSM certification schemes have not been formalized for any period of time, many manufacturers are still unsure as to the best route.

For a complex technology such as GSM, many manufacturers will have to test their products against the standards as part of the development process. Manufacturers with large budgets may choose to equip their own laboratories or subcontract the test and evaluation to a third-party laboratory. Some test equipment will be within financial reach of medium- or smaller-sized manufacturers, but larger sized type-approval test systems will not be as cost-effective as either a tool development or as a compliance tool.

Many manufacturers may choose to continue to use accredited third-party laboratories so that they can obtain a full independent report demonstrating compliance. Test reports like these can add value and credibility to GSM terminal products and can act as a powerful marketing and sales tool. A common strategy will most likely be the application of the TBRs as a minimum requirement.

Whatever strategy is employed, it is clear that manufacturers will have to maintain or even improve their test efforts, to ensure a successful future for global roaming on the GSM communications system.

 

Richard Jacklin is operations manager for RFI's Mobile Communications Group, Basingstoke, Hampsire, UK. He can be reached at richard.jacklin@rfi.co.uk.