Japan, pushing to be the first in the world to deploy third-generation mobile phone systems, is facing a potential deployment delay as the Ministry of Posts and Telecommunications works to solve severe interference issues posed with 3G systems and existing Personal Handyphone Systems networks.
An advisory panel to the MPT, the Telecommunications Technology Council, is putting off submitting its recommendations on a standard for 3G technology until September. Recommendations were expected this month, said an MPT spokeswoman.
The delay, according to the MPT, is due mainly to the TTC waiting for standardization specifications from the 3G Partnership Project 2, a North American standards body spearheaded by the U.S. Telecommunications Industry Association that is developing cdma2000 technology. The MPT was set to push ahead with wideband Code Division Multiple Access technology as the chosen 3G technology standard, but industry consensus reached in recent months now includes a tri-mode CDMA-based standard that encompasses both cdma2000 technology, based on today’s cdmaOne technology, and W-CDMA technology.
Sources close to the MPT, however, indicate interference problems too are causing the delay, and the MPT may have to reconsider its band allocation. Sources say 3G equipment has severely interfered with PHS control channels in early tests of the technology. The PHS band lies directly below frequency reserved for 3G services.
The MPT is considering a number of solutions, including placing a 10-megahertz guard band between the 3G band and PHS band. This would require the MPT to reconsider its plan of granting 20 megahertz of spectrum to three carriers and potentially postpone any spectrum grants. Another solution calls for reducing power output from 3G equipment, which vendors say increases the cost of equipment since carriers will have to deploy more base stations to meet capacity requirements.
The MPT said it expecting to receive TTC’s report in time for carriers to introduce 3G technology in 2001. Time is ticking away for NTT DoCoMo, which needs to migrate to 3G technology quickly because of capacity constraints put on its system by its more than 20 million subscribers. NTT was looking to begin the service in the spring of 2001, but the MPT’s delay is likely to push back the launch toward the end of that year.