The Global Mobile Suppliers Association on Monday rejected Telcom Regulatory Authority of India's proposal to allocate frequencies in the controversial US PCS band (1850-1910 MHz paired with 1930-1990 MHz) to the existing Code-Division Multiple Access operators, saying it would block the migration of cellular companies to 3G services and hamper international roaming.

"GSA rejects this proposal since the upper frequencies of this band is in conflict with the internationally agreed International Mobile Telecommunications- 2000 spectrum plan identified by the International Telecommunication Union for 3G/IMT-2000 systems", it said.

IMT-2000 supports both Wide-band CDMA (GSM path to 3G) and CDMA 2000 (CDMA path to 3G) systems developed for deployment on a fully co-existing basis, thus ensuring all operators and users benefit from 3G for enhanced voice and data services, the largest scale economies and international roaming, it said.

"Deployment of the US PCS band plan, wholly or partially would cause severe interference between current (2G) CDMA base stations and users of 3G systems (WCDMA and CDMA 2000), greatly reducing service quality and performance of 3G systems, raising costs, restricting competition, and laying to waste precious spectrum, which cannot be mitigated against in practical situations", the statement said.

"As a result, the path for GSM and CDMA customers to 3G-enabled voice and data services, would be blocked. No other country has allowed a mixed plan and India would be isolated from the global mobile community. The mixed band proposal must be rejected," it said.

The solution is to move to 3G as quickly as possible. The IMT 2000 core band is standardised to accommodate both WCDMA and CDMA 2000 technologies, and there are no harmful interference mechanisms between the two technologies when deployed in the IMT 2000 core band, Alan Hadden, President, GSA, said.

Since no frequency band is wasted, both GSM and CDMA operators would have a much greater amount of spectrum available to meet their future needs.

All operators would compete on a level playing field, with enough capacity and with access to their logical evolution path, on equal terms, he said ."This would stimulate competition to a new level. Indian consumers and enterprises will benefit and help the economy to further grow", he further added.

GSA has also said that granting of additional spectrum should only be considered after current spectrum has been exhausted. "CDMA operators can already deploy services in the 1800 MHz band as prescribed in the National Frequency Allocation Plan.

CDMA equipment suitable for use at 1800 MHz is widely available commercially in Korea from several infrastructure suppliers. There were 131 handset models in the market serving 17.6 million users at end June 2004 GSA sees no barrier to 180 MHz commercialisation in India", it said

It said that implementation of a mixed US PCS/IMT-2000 band plan would necessitate extensive use of additional complex, costly, non-standardized filtering in all base stations, wide guard bands, intensive site co-ordination between operators, more base stations, and reduce network performance for all operators.