HARMONISED FREQUENCY ARRANGEMENTS FOR THE BAND 698-806 MHZ
Edition: September 2010
The 9th APT Wireless Forum Meeting
13 – 16 September 2010
Seoul, Republic of Korea
APT REPORT ON
HARMONISED FREQUENCY ARRANGEMENTS FOR THE BAND 698-806 MHZ
The burgeoning global demand for ‘anywhere, anytime’ wireless voice and data communications connectivity is imposing increased loads on current public cellular mobile networks in many countries. At the same time, the transition to more efficient digital television technology now sweeping across the world is freeing up radio spectrum previously occupied by analogue television systems. This transition provides opportunity for administrations to respond to the demand for additional spectrum for expanding the capacity of Mobile Services that are becoming recognized as an increasingly important contributor to ongoing economic development and growth.
In particular, a portion of the band 470-806 MHz currently allocated to Broadcasting Services on a co-primary basis in Region 3 will be freed up by the transition to digital television technology, as a so-called “digital dividend”.
In considering how to best use this “digital dividend” administrations may find benefit from guidance in the form of ‘harmonized’ frequency arrangements for use of the band by mobile telecommunications, including IMT.
Region 3 Background
As was highlighted at the World Radiocommunication Conference 2007 (WRC-07), in Article 5 of the ITU-R Radio Regulations, Region 3 already had a long-standing co-primary allocation to the Mobile Service in the band 440-960 MHz, under which particular mobile systems such as IMT could be deployed.
In addition, at WRC-07 a number of Region 3 countries took action to include an explicit identification of the band or portions of the band 698-806 MHz for use by IMT systems. Since that time, many other countries in Region 3 have also begun to consider the use of this same band for future deployment of IMT systems. A harmonized frequency arrangement for the band 698-806 MHz is therefore appropriate to assist Region 3 countries wishing to use the entire band for IMT as well as those administrations considering use of a portion of this band.
Notably, in Region 3, the transition to digital television technology will occur gradually on a country-by-country basis, commencing from around 2012. But, while some countries will make the transition earlier, some other countries in the Region may not undertake the transition until later. To achieve widest consensus, and to maximize the technical and other benefits of adopting harmonized frequency arrangements, it was decided to commence work on developing agreements on the preferred arrangements as early as possible.
AWF work on the development of frequency arrangements for the 698-806 MHz band commenced shortly after WRC-07, in March 2008. During the eighth meeting of the APT Wireless Forum (AWF-8), held in Tokyo, Japan from 29 March to 1 April 2010, consensus was reached in regard to the basic structure of a harmonized frequency arrangement for the band 698-806 MHz. Specifically, the following basic aspects were agreed in relation to an FDD arrangement (refer AWF-8/OUT-08):
A center band gap of 8 MHz may not be supported by current filter technology employed in handsets and it may be practical to chose a value of 10 or 11 MHz;
A pragmatic way forward is to adopt a 2 x 45 MHz plan for FDD; and
The remaining spectrum should be arranged taking into account the concerns expressed at the meeting.
A Correspondence Group (AWF-CG-UHF) was established at the AWF-8 meeting to undertake further studies to assist in determining the final structural arrangements.
Subsequently, during the ninth meeting of the APT Wireless Forum (AWF-9), held in Seoul, Republic of Korea from 13 - 16 September 2010, further discussions were undertaken of the results of studies of the implications of options for a harmonized arrangement for the 698-806 MHz band. At this meeting, consensus agreement was reached on two harmonized frequency arrangements for IMT systems in the 698-806 MHz frequency band.
The two frequency arrangements presented in this report have been derived so as to enable the most effective and efficient use of the spectrum to support IMT systems, while minimizing the impact on other systems or services in these bands and adjacent bands.
Key Considerations for Frequency Arrangements
To maximize the benefits for APT countries, the frequency arrangements for IMT should be harmonized to the maximum practical extent to facilitate interoperability, for economies of scale and to enable seamless roaming by users. As far as practical, these arrangements should also reflect the important principles of:
Efficient usage of the spectrum;
Maximum spectrum block size; and
Appropriate protective measures for services in adjacent bands.
These considerations and their technical implications were studied by the APT Wireless Forum and the relevant technical reports can be found in document AWF-9/INP-74(Rev.2). The studies were based on input contributions received from national administrations, network operators and manufacturers of network equipment, terminal devices and electronic components. Further studies provided to AWF-9 in relation to the compatibility of IMT UE and RNSS systems and implications for the frequency arrangements can be found in documents AWF-9/INP-34, INP-43, and INF-01.
APT Harmonized UHF Band Plan for IMT
Recognizing the need to provide sufficient protection for the services in adjacent bands, the APT Wireless Forum has concluded that a combination of mitigation measures would be necessary, including sufficient guard-band allocations within the 698-806 MHz band.
Based on studies of the various interference mechanisms that may impact services in adjacent bands, it was agreed that spectrum should be allocated as follows:
a lower guard-band of 5 MHz should be allocated between 698-703 MHz; and
an upper guard-band of 3 MHz should be allocated between 803-806 MHz.
It should be noted that some administrations in Region 3, which currently use a 7 MHz or 8 MHz TV broadcasting channel framework in the band 470-806 MHz giving a natural channel boundary at 694 MHz, may also implement an additional 4 MHz ‘external’ guard-band in the 694-698 MHz band segment.
5.1 FDD Frequency Arrangement
Taking into consideration the capabilities of state-of-the-art filter technology, and to maximize the size of upper/lower protective guard-bands, it was agreed that the 2 x 45 MHz FDD structure should include a 10 MHz centre-band gap.
In regard to the ‘duplex direction’ for the FDD arrangement, and recognizing the proliferation of RNSS receivers in pedestrian and vehicular environments and the risk of harmonic interference from user device emissions in the segment 779-805 MHz, it was further agreed that the lower block (703-748 MHz) should be allocated for mobile ‘uplink’ transmissions.
The overall structure of the harmonized FDD arrangement for the band 698-806 MHz is illustrated below in Figure 1:
Notably, the dual-duplexer arrangement is needed to facilitate the mobile terminal implementation while the overlap affords flexibility to administrations in their national spectrum planning.
5.2 TDD Frequency Arrangement
Further, the harmonized all-TDD arrangement for the band 698-806 MHz is illustrated in Figure 2:
Figure 2: Harmonised all-TDD Arrangement of 698-806 MHz band
For this TDD arrangement, taking into account the external 4 MHz guard band (694-698 MHz), a minimum internal guard-band of 5 MHz at the lower edge (698 MHz) and 3 MHz at the upper edge (806 MHz) needs to be considered.
6. Implementation Issues
Finally, it is noted that the specification of appropriate UE out of band emission limits to ensure the coexistence of mobile services with adjacent broadcasting services below the 698 MHz spectral boundary is an important aspect of the conventional duplex arrangement in the band 698 – 806 MHz.
It is also noted that further studies to determine the appropriate UE out of band emission limits and related implementation issues are required.