Spectrum Band Plan 004 - Band and Channel Plan for Narrow-Band High Efficiency Digital Fixed Links in the Bands 1427.0 - 1429.5 and 1522.0 - 1525.0 MHz

Band and Channel Plan for Narrow-Band High Efficiency Digital Fixed Links in the Bands 1427.0 - 1429.5 and 1522.0 - 1525.0 MHz

• Annex 1 Plot of spectrum
• Annex 2 Table of Channel Frequencies
• Annex 3 Region 3 and New Zealand Allocations
  
  

1. Purpose

In April 2001, the Radio Spectrum Management Group of the Ministry of Economic Development initiated a consultation process to determine the demand for high efficiency narrow band digital links in the 1.5 GHz spectrum. The Engineering Consideration Document (ECD) 2001/1 elicited six responses, and confirmed that there is sufficient demand to justify making spectrum available for the purpose.

The consultation process that was undertaken to establish the band is covered in ECD 2001/1, and the associated Finding document.

2. Policy

From the date of publication of this document, applications for radio apparatus licenses for radio transmission and reception protection in the bands 1427.0 - 1429.5 and 1522.0 - 1525.0 MHz for high efficiency narrow band digital point-to-point links will be accepted. Licenses will be granted in accordance with the band and allocation plan criteria in the annexes and section 3 of this document.
 

3. Specific Criteria

3.1  The channel bandwidths and frequencies shall be in accordance with the tables in annex 2 of this document. They make provision for 75, 150 and 250 kHz channels.

3.2  Only point-to-point operation will be permitted.

3.3  Apparatus used must comply with ETSI 300 630 class 3, which specifically requires a minimum 16-level modulation scheme (e.g. 16QAM or equivalent).

3.4  The transmit-receive spacing shall be 94.5 MHz.

3.5  Apparatus used must also meet the general requirements of ETSI EN 300 630, with the exceptions of transmit-receive spacing and channel bandwidth.

3.6  Antennas must have a minimum gain of 16 dBi, a 3 dB beamwidth not greater than 25o, and a front-to-back ratio equal to or greater than 20 dB.

3.7  If operation from an exposed high site would unduly constrain the reuse of the channel(s), a high performance antenna with a half-power beamwidth of less than 8o, a gain of greater than 26 dBi, and a front-to-back ratio not less than 28 dB, such as a 1.8 meter solid parabolic antenna must be used.

4. General Technical Consideration

The band has been designed to alleviate the shortage for medium capacity digital links and to bridge the gap between analogue 1+1 services operating around 400 MHz and digital 2 Mb/s data links operating around 1.5 GHz. As there are only a small number of channels available, especially at the 250 kHz bandwidth, all possible steps need to be taken to ensure maximum reusability of the channels. To achieve maximum efficiency of use, operation in the band is restricted to high efficiency digital links using at least 16 state modulation methods such as 16-QAM, and antennas are constrained in performance to minimise interference potential.

5. Background

New apparatus has become available which encourages more efficient use of the radio spectrum through employment of higher order modulation methods. Digital data rates of up to 800 kbits/second in a 250 kHz wide RF channel can be achieved by using 16-QAM modulation. This gives a spectral efficiency pf 3.2 bits/Hz, as compared with efficiencies around 1.2 bits/Hz for QPSK modulation. By exploiting the new apparatus, even small blocks of spectrum such as those identified in this exercise can make a valuable contribution to relieving the demand for low to medium data rate links.

Verified By:

Manager
Spectrum Planning



Approved By:

Manager
Operational Policy