UTRA FDD Repeater Specification

Acronym: RInImp-REP

UID: 1509

Main responsibility: RAN WG4

 

References for WI " UTRA FDD Repeater Specification "

Document	Title/Contents
RAN_Work_Items_History	WI Description
R4-00012	Repeater Feasibility Study
Impacted Specifications
TS 25.113	Base station and repeater electromagnetic compatibility (EMC)
New Dedicated Specifications
TS 25.106	UTRA repeater radio transmission and reception
TS 25.143	UTRA repeater conformance testing

 

A repeater is a device that receives, amplifies and transmits the radiated or conducted RF carrier both in the downlink direction (from the base station to the mobile area) and in the uplink direction (from the mobile to the base station).

 

The repeater converts the signal down to IF (Intermediate Frequency), amplifies and filters it and converts it back to RF. The repeater does not process the signal in base band hence it cannot decode any information. For this reason, UTRA TDD repeaters have been considered out of scope: without the information contained in the signalling, the repeater cannot know when to transmit in each direction, uplink or downlink.

 

Repeaters have been used in 2G networks as a cost effective solution for extending coverage in sparsely populated areas or environments with particular propagation conditions such as buildings, tunnels, subways, stadiums, etc.

The following figure shows a simple schema of the use of a repeater.

Use of a repeater

In the frame of this work, two new specifications are produced. TS 25.106 contains a set of Radio requirements for repeaters, and TS 25.143 specifies how this requirements should be tested. The following parameters are defined in Release 4:

1) Maximum output power: this is the difference between the actual power and the manufacturer's rated power. It has to be noted that 3GPP does not specify Maximum TX powers, this is a matter of national regulation.

2) Frequency stability, which is the frequency deviation of the output signal with respect to the input signal

3) Out of band gain: the undesired amplification of signals out of the operation band of the repeater.

4) Unwanted emissions. There are two set of limits: Out of band emissions, for the frequencies immediately outside the operating band; and Spurious emissions, from 9 KHz to 12,75 GHz. For the latter, particular requirements are specified for the cases of co-existence with various technologies (GSM, UTRA TDD,...)

5) Modulation accuracy, to ensure that the quality of the source signal is not degraded by the additional processing in the repeater. There are two requirements: Error Vector Magnitude and Peak Code-Domain error

6) Input Intermodulation: the interference generated in the operating band in the repeater as a result of the presence of interfering signals on frequencies other than the operating band shall be less than a certain limit.

7) Output Intermodulation. This is a similar requirement as above, but in this case the interfering signals reach the repeater through the output port.

These requirements are roughly based on FDD Base Station requirements, only 3) and 7) address issues related to the operation of Repeaters. Notably, undesired interference or amplification in adjacent bands which might belong to a different network operator. Additional requirements are added in later Releases, as the particularities of operation of repeaters in a WCDMA network become evident.

The use of repeaters in the radio access is transparent to upper layers. However, there is an impact in the OTDOA method used in Location Services due to an increase in the path delay not originated by an increase in distance.

GSM-only new Features

MHz spectrum support

 

Acronym: 700SS

UID: 2403

Main responsibility: GP

 

References for WI " 700 MHz spectrum support "

Document	Title/Contents
GP-000449	WI Description
Impacted Specifications
TS 51.010   TS 51.021   TS 43.022   TS 43.030 TS 44.018 TS 24.008 TS 45.001 TS 45.005 TS 45.008	Mobile Station (MS) conformance specification; Part 1: Conformance specification Base Station System (BSS) equipment specification; Radio aspects Functions related to Mobile Station (MS) in idle mode and group receive mode Radio network planning aspects Radio Resource Control (RRC) protocol Core network protocols; Stage 3 Physical layer on the radio path; General description Radio transmission and reception Radio subsystem link control
New Dedicated Specifications
	None

 

Contains:

	GERAN support for the 700 MHz band	GP-000450
	GERAN MS Conformance test for 700 MHz band	GP-000451
	GERAN BTS Conformance test for 700 MHz band	GP-000452

 

This feature provides GERAN system support for 700 MHz frequency band.

The commercial use of the 746-764 MHz and 776-794 MHz bands may be launched by US operators who have shown interest to provide GSM services on those new bands. In order to be one candidate technology to be used as a cellular service for those bands, the GSM specifications are now including the support of the so-called 700 MHz spectrum.

This was widely facilitated by the band independent format of GSM specifications: almost all aspects, as Service, MMI, Charging or Security aspects, are the same as in other bands (400, 850, 900, 1800 and 1900 MHz bands).

When considering GSM for the 700 MHz band, potential extension on further frequency bands like 430-450 MHz, 698-746 MHz, 1710-1885 MHz, 2500-2690 MHz was considered, e.g. in the channel numbering.

Improvements of UMTS and GSM pre-Release 4 features