3.1 Expected technical developments and likely demand

26. There are a number of potential uses of the 2.3/2.5 GHz bands. These include:

• WiMAX wireless broadband;
• IMT 2000 cellular;
• Remote rural uses, in particular CMAR¹ services;
• Point to point linking uses and outside broadcast media linking.

27. These uses are discussed briefly below, with a particular focus on broadband uses in the light of government policy to facilitate and accelerate the availability and uptake of broadband services. 
28. A particular issue is that WiMAX is currently only available with TDD (time division duplex) technology which uses a single frequency channel to transmit signals in the upstream and downstream directions. In contrast, IMT 2000 cellular and other services use FDD (frequency division duplex) technology which requires separated “transmit” and “receive” frequencies. In general terms, the same frequencies cannot be used by both TDD and FDD technologies at the same time.

WiMAX wireless broadband

29. WiMAX² is a relatively new technology which aims to provide high speed wireless data over relatively long distances (compared to Wi-Fi) and in a variety of ways, from fixed point to point links to fully mobile services. It is expected to provide improved wireless broadband performance and to be eventually included in a range of consumer devices including laptops. 
30. There is no uniform global spectrum allocation for WiMAX. In the US the biggest segment available is in 2.5 GHz, while elsewhere the most likely bands will be around 3.5 GHz, 2.3/2.5 GHz, or 5 GHz. The 2.3/2.5 GHz band is likely to be the most important in Asia, although some countries in Asia are likely to use 3.3 GHz.

Recent mobile WiMAX spectrum development

31. Recently, an ITU Working Party (WP 8F) made recommendations for a new radio interface for IMT-2000 based on the mobile WiMAX standard. Following a further meeting to be held in September, a recommendation is likely to be forwarded to the ITU Radiocommunications Assembly in October 2007 for consideration. The effect of the recommendation, if accepted, is to recognise WiMAX as an IMT 2000 technology. (Traditionally IMT-2000 technologies have only included cellular technologies like CDMA2000 and WCDMA (UMTS)). This change is expected to give a boost to the development and use of mobile WiMAX equipment in any of the bands identified for IMT 2000 including the 2.5 GHz band.

Minimum frequency requirements for WiMAX provision

32. Most submitters on the 2.3 GHz auction discussion paper considered that 30 MHz plus a guardband (of 5 MHz) was the minimum necessary for WiMAX services. 
33. It is highly likely that some WiMAX providers will want more bandwidth than this in order to provide advanced WiMAX services such as interactive video. Up to 100 MHz has been mentioned by some commentators.

Lack of technology certainty

34. The WiMAX technology path is not certain. WiMAX wireless technologies are undergoing rapid change and standards are not completely settled. In particular it is unclear whether the first or dominant WiMAX band for major international deployment will be 2.3 GHz or be 2.5 GHz. It is also unclear whether mobile WiMAX will be able to effectively compete with the cellular IMT2000 technologies. WiMAX may also be available using FDD technology in future.
35. WiMAX equipment available in the next few years is unlikely to be able to be re-tuned to operate in either the 2.3 or 2.5 GHz bands, so parties wishing to acquire spectrum for WiMAX use will need to make assumptions as to likely international trends.

Commercial viability of multiple WiMAX providers

36. Cabinet decisions on the 2.3/2.5 GHz auction set an acquisition limit of approximately 35 MHz (including guardbands). Potentially this would allow sufficient spectrum to accommodate up to six nationwide providers of WiMAX.
37. It is questionable whether a small country like New Zealand can sustain this number of WiMAX providers. Note though that:

• There are other demands for 2.3/2.5 GHz spectrum in addition to WiMAX.
• It is not the government’s role to pre-judge likely commercial outcomes and to restrict the availability of spectrum to ensure commercial viability of spectrum holders.

38. There is a case however for allowing early trading of spectrum to allow for re-allocation and/or consolidation of spectrum if that makes sense for commercial viability reasons.

IMT 2000

39. IMT 2000 is a 3G cellular (mobile) technology. The traditional telecommunications companies may be interested in 2.5 GHz spectrum in particular for future cellular (4G) services. Such services are likely to be IP-based and offer broadband capability. Again, this technology is characterised by rapid technology developments and considerable uncertainty. 

Minimum frequency requirements for IMT 2000 cellular services

40. Cellular services use FDD technologies which require separate transmit and receive bands. In MED’s view, a viable minimum spectrum assignment for these technologies is 15 MHz x 2. (A guardband/separation of some 120 MHz is required between the receive and transmit frequencies in the 2.5 GHz band.)
41. Again however, telcos are likely to prefer to acquire much larger bandwidth (assuming they are interested in this spectrum for cellular uses) to allow for potential technology development. It is likely that 20 MHz paired will be the building block for future IMT Advanced (4G) services.

Rural CMAR services

42. Telecom currently uses the 1.5 GHz band to provide ‘CMAR’ services. Telecom is seeking spectrum in 2.3 GHz or 2.5 GHz bands to allow these to be replaced with technology that can provide broadband as well as telephony services. 
43. CMAR uses FDD technology which is incompatible with WiMAX TDD technologies in the same spectrum and coverage area.
44. A key issue is the extent to which Telecom or other service providers may use a managed spectrum park for the provision of remote point to multi-point services. The likely geographical separation between rural and urban services may assist sharing between competing services.

Point to point services

45. A further potential use of 2.3 GHz and 2.5 GHz spectrum is for point to point links for telecommunications backhaul services, especially in remote areas where it is unlikely to conflict with broadband access services. 

It is also possible that outside broadcast and electronic newsgathering services may continue to be used in areas where there is no conflict with broadband services.

²WiMAX stands, for Worldwide Interoperability for Microwave Access.