5. Radio Frequency Identification Devices

5.1 Background

5.2 Overview

5.3 Review of 135kHz, 13.56MHz and 433MHz Bands

5.4 Review of 860 to 960MHz

5.5 Conclusions for 860 to 960MHz

5.6 Review of 2400 to 2483.5MHz

5.1 Background

Radio Frequency Identification Devices (RFID) are anticipated to become one of the most prolific users of very low power transmissions in the next decade. The technology is now available to economically include an RFID into raw products, components, finished products and bulk containers so that they can be tracked through international distribution systems. There are many diverse applications each requiring a variation on the technologies and radio spectrum that is available.

The RFID device itself may be passive or active. A passive device is not a radio transmitter. Its purpose is to modulate the field generated by the reader when within close range. The frequency and power of the reader will depend on the range required, the amount of data to be transferred and the number of RFID devices to be read simultaneously. Passive devices are anticipated to be the dominant technology for RFID.

An active RFID emits its own signal when triggered by a reader and is regarded as a very low power transmitter. Active devices are limited to specialised uses and generally operate in the existing ISM bands.

5.2 Overview

The ITU-R Recommendation SM.1538-1 10 defines the nature of RFIDs. However there is no guidance on the preferred spectrum bands.

The International standards series ISO/IEC FCD 18000 11 are in development. They include the following parts which provide guidance on the spectrum bands of interest:

5.3 Review of 135kHz, 13.56MHz and 433MHz Bands

The bands at 135kHz and at 13.56MHz use inductive coupling to energise the RFID tag. The current New Zealand SRD allocations of 10mW at 0.03 to 0.19MHz and 100mW in the ISM band 13.55 to 13.57MHz meet the requirements for this purpose.

Frequencies 433MHz and above generally use back scatter to read the RFID device.

The ISM band 433.05 to 434.79MHz appears to have limited use for RFID. It is provided for in New Zealand by the 25mW power level under the SRD GURL.

Proposal 5.a

The Ministry proposes not to change the current allocations in the135kHz, 13.56MHz and 433MHz bands as they make sufficient provision for RFID.

5.4 Review of 860 to 960MHz

The band 860 to 960MHz is of particular interest for RFID because it provides a useful compromise between range and data capability for distribution chain management in the retail industry. Wal Mart in USA are an early adopter of this technology and have standardised on part of this band. However there are no sub bands in this range which are available internationally because of the adjacent mobile allocations.

The band 902 to 928MHz is also in demand for Wireless Local Networks (refer section 4.3).

In Europe the ETSI proposals for RFID in the 865 to 870MHz band have power levels varying from 2 Watts to 0.1 Watt depending on the frequency band. These proposals are still under consideration so there may be further changes.

In New Zealand the band 864 to 868MHz is allocated to any type of short range device with an e.i.r.p. limit of 1W and spread spectrum devices with e.i.r.p. up to 4W.

The band 864 to 868MHz is not available for SRD in USA and Australia because of licensed mobile allocations.

A summary of the allocations in the 864 to 868MHz band is provided in the table below.

In USA the Region 2 ISM band 902.5 to 928 is targeted for RFID. A radiated power of 4W is allowed with devices using digital modulation or spread spectrum (ref FCC Part 15.247).

Australia has an allocation in their LIPD Class Licence 12 for 1W devices using digital modulation or spread spectrum at 915 to 928MHz (which is part of the Region 2 ISM band).

New Zealand has two SRD allocations in the 902 to 928MHz band. The first provides for 1W transmitters in the band 921 to 929MHz. The other provides for 3mW telemetry and telecommand transmitters from 915 to 921MHz. The power is limited in the 915 to 921MHz band because it is shared with licensed Studio Transmitter Links.

A summary of the allocations in the 902 to 929MHz band is provided in the table below.

5.5 Conclusions for 860 to 960MHz

It would appear inevitable that differing bands will be allocated for RFID in Europe and USA. However the desire for international roaming of these devices is likely to produce dual band or wide band systems. With New Zealand needing to accommodate RFID from both regions the Ministry is considering some cautionary steps to minimise the impact of RFID growth at a later date. One step is to freeze the issuing of further mobile licences in the 868 to 870MHz band. The other is to freeze the issuing of further licences in the band 915 to 921MHz for use by Studio Transmitter Links (as also proposed for wireless LANs).

It is also possible that ultra wide band (UWB) technology will be used in some RFID devices. This enables the RFID to provide location data as well as the identity which can be important in crowded areas such as warehouses. UWB devices are reviewed in section 9.

Proposal 5.b

The Ministry invites comment on the anticipated growth in the use of the band 860 to 960MHz band for RFID, especially in the international distribution chain markets.

The Ministry also invites comment on the proposal to freeze the availability of mobile licences in the band 868 to 870MHz and STL licences in the band 915 to 921MHz with possible migration out of these bands in the future.

5.6 Review of 2400 to 2483.5MHz

The band 2400 to 2483.5MHz is already available for a wide variety of ISM and communication devices. The current conditions of use allow for any type of use and there is no apparent need to change the current GURL.

This band is also heavily used by wireless LANs and details of this application are available in section 4.5.

Proposal 5.c

The Ministry proposes not to change the current allocations in the 2400 to 2483.5MHz band as they make sufficient provision for RFID.

10 Recommendation ITU-R SM.1538.1 - Technical and operating parameters and spectrum requirements for short-range radiocommunication devices.

11 ISO/IEC FCD 18000 - Standard Information Technology -- Radio-Frequency Identification for Item Management

12 ACA Radiocommunications Class Licence (Low Interference Potential Devices) 2000