PHS MoU Document
B-IW4.00-01-TS
Title: Public Personal Handy-Phone System : Interworking Between
Networks Operating At Bit Rates Less than 64 kbit/s With Public
PHS Network
Version: 01
Date: July 31, 1998
PHS MoU Classification: Unrestricted
List of contents:

1. General
2. Scope
3. Principles
4. General interworking configuration
5. Examples of applications
Annex A Glossary and Abbreviations
Annex B Network interworking between a public PHS network and a
Digital Public Land Mobile Network (D-PLMN)
Appendix I D-PLMN

Number of pages: 7PHS MoU Group
c/o Association of Radio Industries and Businesses (ARIB)
14F, Nittochi Bldg., 4-1, Kasumigaseki 1-choume, Chiyoda-ku, Tokyo 100, Japan
TEL +81-3-5510-8599 FAX +81-3-3592-1103© PHS MoU Group1998

PHS MoU Document
B-IW4.00-01-TS
Version01

History of Revised Versions
DateOutline
July 31, 1998 EstablishedB-IW4.00-01-TS

Public Personal Handy-Phone System: Interworking Between
Networks Operating At Bit Rates Less Than 64 kbit/s
With Public PHS Network< Summary >1. Relationship with International Standards
This specification specifies the interworking arrangements between a public PHS network andnetworks operating at bit rates less than 64 kbit/s based on ITU-T Recommendation I.525.
2. Differences to/from ITU-T Recommendations
The differences between this specification and ITU-T Recommendation I.525 are shown in table 1/BIW4.00-01
Table 1/B-IW4.00 Differences between the specification B-IW4.00 and ITU-T I.525
Item
Difference
Reasons
1) description for B-ISDN
Deletion in this specification. Public PHS network does notsupport B-ISDN services.
2) Packet mode service
Deletion in this specification. Public PHS network does notsupport packet mode services.
3) Interworking with IDN-32
Deletion in this specification. Public PHS network does notinterwork with IDN-32.
4) Interworking with access
Deletion in this specification. Public PHS network does notnetworks
interwork with access network
through V5.1 or V5.2 interface.

3. References
ITU-T Recommendation I.525
4. Items for Further Study
Following items are recognized to be under study:a) Principles and objectives for end-to-end service quality, compatibility, and essential service
support.
b) Support of roaming function between D-PLMN and public PHS network

B-IW4.00-01-TS(1)

B-IW4.00-01-TS
Public Personal Handy-Phone System: Interworking Between
Networks Operating At Bit Rates Less Than 64 kbit/s
With Public PHS Network

Contents

1. General .................................................................................................................................................

12. Scope ....................................................................................................................................................

1

3. Principles .............................................................................................................................................

1

4. General interworking configuration ....................................................................................................

1

5. Examples of applications .....................................................................................................................

2Annex A GLOSSARY and ABBREVIATIONS................................................................................... 3
Annex B

Network interworking between a public PHS network and a Digital Public Land Mobile

Network (D-PLMN) ......................................................................................................................

4Appendix I D-PLMN................................................................................................................................

7B-IW4.00-01-TSi1. General
There is an increasing number of public digital networks being establishedwhich rely on bit rates ofless than 64 kbit/s to support data applications in the mobile environment. Though some of these may
be national options or specialized applications, in many cases these networks will require to interwork
with public PHS networks.
2. Scope
The purpose of this specification iss to describe the interworking arrangements between a public PHS
network and networks operating at bit rates less than 64 kbit/s. Examples of such digital networks
include:- mobile networks, including cellular networks;- personal communication networks (PCN).
3. Principles
Networks operating at less than 64 kbit/s and interworking with public PHS network shall follow
internationally agreed 64 kbit/s based ISDN interface standards for interconnecting with ISDN. In
particular, they shall ensure time slot sequence integrity of the information conveyed in a 64 kbit/schannel at the interworking point. Any adaption and interworking functions to public PHS network
following standard ISDN interfaces will be provided within the specialized network (i.e. networkswith rates less than 64 kbit/s).
Principles and objectives for end-to-end service quality, compatibility, and essential service support
are for further study.
4. General interworking configuration
Figure 4-1/B-IW4.00 shows the general reference configuration for interworking.

<64k bit/s
networkIWFpublicnetwork

PHS

Figure 4-1/B-IW4.00 General configuration for interworking between public PHS network
andnetworks which operate at bit rates of less than 64 kbit/s

5. Examples of applications
5-1

Annex B describes an example of interworking of a Digital Public Land Mobile Network (DPLMN) with ISDN.

B-IW4.00-01-TS 1

Annex A GLOSSARY and ABBREVIATIONS***A******B******C******D******E******F******G******H******I******J******K******L******M******N******O******P******Q******R******S******T******U******V******W******Y******Z***

2

B-IW4.00-01-TS

ABBREVIATIONS
D-PLMN
ISDN
IWF
PS
UDI
MAP
INAP
SS No.7 ISUP
PHS

Digital Public Land Mobile Network
Integrated services digital network
Interworking function
Personal station
Unrestricted Digital Information
Mobile Application Part
Intelligent Network Application Part/Protocol
Signalling System No.7 ISDN User Part
Personal Handy-Phone SystemB-IW4.00-01-TS 3

Annex B Network interworking between a public PHS network and a Digital Public Land
Mobile Network (D-PLMN)

B.1 General
In a D-PLMN users are typically provided with digital user network access capabilities atsignificantly less than 64 kbit/s for efficient radio frequency use, which may be different for speechand data, and a separate low bit rate signalling access. Different D-PLMNs can operate at different bitrates.
B.2 Scope
The purpose of this annex is to describe the general arrangements for interworking between a DPLMN and the public PHS network.
B.3 Interworking configuration and network characteristics
B.3.1 Interworking configuration
See Figure 1/B-IW4.00.
B.3.2 Key D-PLMN and public PHS network characteristics and related interworking functions
Table B1/B-IW4.00 identifies the key characteristics of a D-PLMN and a public PHS network,
indicating possible interworking functions to accommodate dissimilar characteristics.
B.3.3 Services suitable for D-PLMN - public PHS network interworking
B.3.3.1 Services suitable for calls initiated in a D-PLMN and terminated in public PHS networki)ii)

Circuit mode service usable for speech information transfer;
Circuit mode service usable for data.

B.3.3.2 Public PHS network bearer services suitable for calls initiated in public PHS networkand terminated in a D-PLMNi)ii)iii)

4

circuit-mode 64 kbit/s, 8 kHz structured bearer service, usable for speech informationtransfer;
circuit-mode 64 kbit/s, 8 kHz structured bearer service, usable for 3.1 kHz audio informationtransfer;
circuit-mode 64 kbit/s unrestricted, 8 kHz structured bearer service

B-IW4.00-01-TS

Table B1/B-IW4.00

Key D-PLMN and public PHS network characteristics and possibleinterworking functions required
IWF

Subscriber interface
User-network signalling
Inter-exchange signalling

D-PLMN
DigitalOut-band
SS No.7 ISUPMAP

Information transfer mode

CircuitCircuit connect based Circuiton 64 kbit/s
Transcoding echo
speech based on 64controlkbit/s PCM

Information transfer capability Low rate speech

Additional service

Signal mapping
Signal mapping
For further study

Public PHS network
DigitalOut-bandSS No.7 ISUP
B-IFx.50 (INAP)

3.1 kHz audio

Modem pool

3.1 kHz audio on 64kbit/s PCM

Low bit-rate dataRate adapting

64kbit/s UDI

Mobile specificservicesFor further study

For further study

For further study

For further study

public PHS specificservices

B.3.4 Functional requirements for D-PLMN - public PHS network interworking
B.3.4.1 Interworking between signalling systems
When the D-PLMN and public PHS network use ISUP, no extra interworking functions are required.
B.3.4.2 Interworking for speech
The IWF in a D-PLMN has a transcoder to convert between the low bit-rate speech coding in DPLMN and the standard 64 kbit/s coding in public PHS network (see B1/B-IW4.00). The low bit-ratespeech coding in D-PLMN may have a processing delay sufficiently long to require an echo canceller
to cancel the echo from the public PHS network side.
B.3.4.3 Interworking for data
Since the complex voice coding of D-PLMNs can not pass voice-band data, when data transmission isrequired, the voice codec must be bypassed. One mechanism for transmission across the public PHS
network would be for the low bit rate of the D-PLMN (e.g. 8 kbit/s) to be rate-adapted to 64 kbit/s
data by the IWF. This is illustrated in Figure B3/B-IW4.00.

B-IW4.00-01-TS 5

MobileTerminalD-PLMN

IWF

Public PHS

Public PS

networkLow bit-rate encodedspeech

64 kbit/s•/Ab :rate adaption
radio access
Note: For interworking within public PHS network, see B-IW1.01
Figure B1/B-IW4.00
network

General configuration for interworking between public PHS
and D-PLMN showing transcoding IWF

Public PHS

MobileTerminal

D-PLMNIWF

Low bit-rate data

network

Public PS

64 kbit/sb :rate adaption
radio access
Note: For interworking within public PHS network, see B-IW1.01
Figure B2/B-IW4.00
network

General configuration for interworking between public PHS
and D-PLMN for data

B.3.4.4 Supplementary service interworking
A D-PLMN may be provided with similar to identical supplementary services to those in the publicPHS network.
Frequently, the supplementary services will be required to operate across networks, and interworking
between a D-PLMN and the public PHS network requires interworking of signalling, notification andindications. Additionally, procedure compatibility may sometimes need to be assured before
interworking of a supplementary service can be allowed.

6B-IW4.00-01-TS

Appendix I

D-PLMN

A.I.1 General
A D-PLMN is based on the following principles:the digitalization of the user network access for each user, allowing the establishment of an
all-digital network;
the provision of a single low bit-rate communication channel and a signal low bit-rate
signalling channel to and from terminals of this network.
A.I.2 Scope
The purpose of this appendix is to describe the main features of a D-PLMN which are needed for, andaffect, the interworking functions specification.
A.I.3 Principles
A D-PLMN consists of a digital switching network connected to and serving digital radio transceiver
stations which can be connected by radio links on an on-demand basis to mobile terminals within theirradio-coverage areas.
Because of the nature of the radio links, only relatively low bit rates may be available for the transportof speech or data, and for speech, complex encoding is required. Additionally, error correction coding
and other techniques are needed to overcome excessive bit error rates during fades and close to theedge of the radio-coverage area. These result in transmission delays sufficient to require echo control
within the D-PLMN for speech. Speech encoding used by D-PLMN is not suitable for conveying
voice-band data. For data, echo control is removed.
A D-PLMN is constructed using the following equipment:
digital radio transceiver stations, incorporating digital multiplexers;
digital transcoders (for radio path to standard PCM transcoding);
digital switching equipment (mobile subscriber switching modules and transit switchingmodules);echo controllers;
digital transmission systems;
interworking units (Note);
operation and maintenance modules.
Note - Interworking units provide the interface to public PHS network, ISDN, PSTN, etc.

B-IW4.00-01-TS 7