PHS MoU Document
D-DT1.00-01-TS
Title: Private Personal Handy-Phone System : Personal Handy-Phone
Systems (PHS) and Global System for Mobile Communications(GSM) Dual Mode Terminal
Version: 01
Date: July 31, 1998
PHS MoU Classification: Unrestricted
List of contents:
Foreword
1. Scope
2. Terminal configurations
2.1 General
2.2 Terminal Types
2.2.1 Terminal Type 1
2.2.2 Terminal Type 2
2.2.3 Terminal Type 3
3. Mode Selection
3.1 General
3.2 Mode selection
3.2.1 General requirements
3.2.2 Additional requirements
3.3 Engineering considerations
3.3.1 Excessive mode switching
3.3.2 Missed paging
3.3.3 External handover between air Interfaces
3.3.4 Call Forwarding
4. Principles for type approval for DMTs
4.1 Telephony requirements
4.2 Spectrum protection requirements
4.2.1 Testing philosophy
4.2.2 Testing requirements
5. References
6. Abbreviations and Terminology
6.1 Abbreviations
6.2 Terminology

Number of pages: 12

PHS 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
D-DT1.00-01-TS
Version01

History of Revised Versions
Date
OutlineJuly 31, 1998 EstablishedPrivate Personal Handy-Phone System :Personal Handy-Phone System(PHS) and Global System for Mobile communications(GSM)
Dual Mode Terminal- Minimum Set Specification -Contents

Page

Foreword ..................................................................................................................................... 1
1 Scope ................................................................................................................................... 1
2 Terminal configurations ....................................................................................................... 1
2.1
General .......................................................................................................................... 1
2.2
Terminal Types .............................................................................................................. 2
2.2.1
Terminal Type 1 ......................................................................................................... 2
2.2.2
Terminal Type 2 ......................................................................................................... 2
2.2.3
Terminal Type 3 ......................................................................................................... 33
Mode Selection .................................................................................................................. 3
3.1
General .......................................................................................................................... 3
3.2
Mode selection .............................................................................................................. 3
3.2.1
General requirements .................................................................................................. 3
3.2.2
Additional requirements .............................................................................................. 5
3.3 Engineering considerations ............................................................................................... 6
3.3.1
Excessive mode switching ........................................................................................... 6
3.3.2
Missed paging ............................................................................................................. 7
3.3.3
External handover between air Interfaces ..................................................................... 7
3.3.4
Call Forwarding ........................................................................................................... 7
4
Principles for type approval for DMTs ............................................................................... 8
4.1
Telephony requirements .................................................................................................. 8
4.2
Spectrum protection requirements .................................................................................. 8
4.2.1
Testing philosophy ....................................................................................................... 8
4.2.2
Testing requirements .................................................................................................... 8
5
References .......................................................................................................................... 10
6
Abbreviations and Terminology ......................................................................................... 10
6.1
Abbreviations .................................................................................................................. 10
6.2 Terminology........................................................................................................................... 11

D-DT1.00-01-TSi

Foreword
The purpose of this document is to specify the minimum common technical requirements of the dual
mode terminal (combined Personal Handy-phone System/Global System for Mobile
communications (PHS/GSM) ) and to consider the related engineering requirements and issues toimplement the PHS/GSM dual mode services.
This document is also prepared intending that the combined PHS and GSM dual mode terminals
which will be used in integrated service environment for fixed network and mobile network such as
PHS home/office cordless services and GSM mobile services with one combined terminal. For an
example, a dual mode terminal can be used as a GSM in an outdoor environment and as a homecordless telephone in home. The automatic connection of calls on the GSM number to thehome/office-cordless telephone will be implemented through the additional function (follow-me
service) in the PLMN.
1

Scope

This document focuses on possible early implementations and will open the first edition of thetechnical specification in the sense how dual mode terminals (DMTs) can be type approved using
existing documents and new additional specifications. It is also covered to investigate radio andnetwork aspects and to clarify the problems related to dual-mode terminal.
For Personal Handy-Phone System (PHS), only Private Application is considered in thisspecifications and Public Application will be considered in the future.
For Global System for Mobile communications (GSM), both phase 1 and phase 2 specifications
shall be considered.
2

Terminal configurations

2.1

GeneralA DMT for PHS and GSM is a terminal with one PHS part and one GSM part that is controlled by acommon Interworking part which controls one common Human Machine Interface(keypad, display
and menu functions). A reference configuration for the DMT is shown in Figure 1.
Antenna installation method is not specified here ; separate antennas for PHS and GSM shall besuitable for testing purpose and country regulations but an integrated antenna installation forcommon use will be also suitable for user operation.

D-DT1.00-01-TS

1

Human MachineInterface• •Interworking
PHS

GSM

Figure 1 DMT Basic Configuration
2.2

Terminal Types

Dual mode terminals are categorized basically three types of configurations denoted as types 1-3.
The essential differences between these terminal types are summarized in Table 1.
These terminals can only transmit on one of the air interface at the time.

Table 1 Summary of terminal types
Terminal
Types

Air interface
Selection

Simultaneous
Receiving *1

Simultaneous
Dual-Mode
Receiving *2
Type 1
ManualNo
No
Type 2
Automatic
Yes
No
Type 3
Automatic
Yes
Yes*1 Simultaneous receiving: paging is available only at the active air interface, but backgroundscanning is performed at the non-active air interface.
*2• Simultaneous dual-mode receiving: paging is available at both air interfaces.
2.2.1 Terminal Type 1
This type is the simplest type that is just combined of two terminals into single housing case.
a. Mode selection from one air interface to the other is performed by manual.
b. This type terminal operates only active communication either air interface at the same time, theother air interface is non-active communication.(It means this type dose not allow to operate over
PHS and GSM air interfaces at the same time.)
2.2.2 Terminal Type 2
a. The type 2 terminal monitors both air interface to determine which will give the best operation.
b. Mode selection from one air interface to the other is performed automatically by RSSI
measurements.
c. For automatic mode switching, the terminal may be pre-assigned a priority air interface by theuser or terminal itself.
d. If the terminal is in active communication status, any paging is not allowed at other non-active
air interface.

D-DT1.00-01-TS2

2.2.3 Terminal Type 3
a. The type 3 terminal monitors both air interfaces simultaneously for RSSI measurements and forpaging.
b. Mode selection from one air interface to the other is performed automatically.
c. Once the terminal enters into active communication at one air interface, the terminal cannot
respond to paging on the other air interface.
3

Mode Selection

3.1

GeneralA DMT is a terminal comprising both PHS and GSM parts. The DMT is in either PHS or GSM
mode. When in either mode, the DMT operates as the corresponding single mode terminal (exceptthat it may perform background scanning) and shall fully comply with the relevant specifications forthat single mode terminal ( ETS 300 607 [6] for GSM. ARIB Standard RCR STD-28 [1] for PHS),
unless specified in the present document.
When one mode is entered the DMT operates like a single mode terminal that is switched on. Whenone mode is left the DMT operates like a single mode terminal that is switched off. When the DMT
switches mode, it leaves the first before entering the second, and operates as two single modeterminal where the first is switched off before the second is switched on.
Switching between the two modes is done manually by the user or automatically by the terminal.
The DMT shall not switch mode when in active communication. Automatic mode switching can be
executed based on background scanning or loss of coverage.
3.2 Mode selection
3.2.1 General requirements
3.2.1.1

Communication mode

A DMT equips at least the following two communication modes against both air interfaces;
a. PHS communication mode which is active status on PHS air interface
b. GSM communication mode which is active status on GSM air interface
3.2.1.2

Mode indication

A DMT indicates to the user the current mode of status which air interface is in active.
3.2.1.3

Mode selection

The DMT supports the following two mechanisms for mode selection:a. Manual selection mechanism ( applied to Type 1, Type 2 and Type 3)
b. Automatic selection mechanism ( applied to Type 2 and Type 3 )Basic concept of mode selection mechanism is illustrated in Figure 2.

D-DT1.00-01-TS3

3.2.1.4

Manual mode selection mechanism

Manual selection mechanism support to user an opportunity to change the present mode to othermode by manual at any time when the DMT is not in active communication status.
3.2.1.5

Automatic mode selection mechanism

a. This mechanism gives a certain decision capability to switch between both air interfaces by
supporting automatic monitoring function to listen for broadcasting channels and or paging
channels against both air interfaces periodically or simultaneously.
b. Mode selection of Type 2 terminal from one air interface to the other is performed automaticallyby the result of RSSI measurements.
c. Mode selection of Type 3 terminal is performed automatically to the mode in which paging
processing is activated.
3.2.1.6

Last selection mechanism at switch-on

At every switch-on, the DMT may use the last selection mechanism, as the default selection
mechanism.
If the DMT had manual mode selection activated when switched-off, it will go active in the samemode when switched-on.
3.2.1.7

SIM control

a. If the DMT with no or invalid SIM inserted had automatic mode selection activated whenswitched-off it may go active (at switch-on) in PHS mode.
b. In PHS mode SIM access is not allowed.
3.2.1.8

Manual resurrection of modea. A DMT can be changed forcibly the present mode to the other mode by a user at any time as longas the DMT is not in active communication status.
b. The manual mode selection mechanism supports the mode change to switch directly to non-activemode whether the other air interface is identified or not.
3.2.1.9

Automatic change of network

For automatic switching between networks there are two different behaviors of the DMT.
a. it stays locked to the selected system until it leaves the coverage area and then starts selecting theavailable network with the highest priority; orb. it could continuously scan for available networks and initiate a change of network when it finds
one with higher priority than the one presently attached to.

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4

Switch-on
Loss of coverage

Loss of coverage
Mode
Selection

PHS Mode

GSM Mode-Manual selection mechanism-Automatic selection mechanism
Figure 2 Basic concept of mode selection mechanism

3.2.2 Additional requirements
3.2.2.1

Automatic mode selection procedure

a. A DMT(type 2 and type 3) selects automatically GSM or PHS mode with respect to the priority
air interface which has been pre-assigned by the user.
b. [For Type 2 DMT]: Three cycles are given in the automatic mode selection procedure.
One cycle for loss of coverage, one for background scan where a priority air interface is notfound, and one for change of mode by the result of the background scanning. These switchingcycles between priority and non-priority modes are shown in Figure 3.
When the automatic mode selection mechanism is activated, the DMT behaves like a single PHS
or GSM phone terminal.
c. [For Type 3 DMT]: Type 3 DMT supports simultaneous dual-mode receiving. In case of originating call,Type 3 DMT selects the priority mode first, and then non-priority mode automatically.
Switch-on
Loss of coverage
Priority ModeYes

Is priority
PHS
Mode
mode
available?
No

Background scan

Non-Priority
Mode
Loss of coverage

Figure 3 Automatic mode selection cycles in Type 2 terminal

D-DT1.00-01-TS5

3.2.2.2

Priority mode, non-priority modea.

In the case of a loss of the coverage the DMT may switch to another air interface based on
predetermined time control rules.
b If a priority air interface is detected, the Type 2 DMT may switch to the priority air interface in
active. The Type 2 DMT needs not execute any background scan for non-priority air interface aslong as it is in the priority mode and normal service is available.
While the Type 2 DMT is in non-priority mode and normal or limited service is available, theType 2 DMT may execute background scanning for priority air interface periodically. If thepriority air interface is detected again, it may return to the mode again based on predetermined
time control rules.
c. Type 3 DMT is enable to receive the paging channel of non-priority mode also while the priority airinterface is set.
Note: While the DMT is in priority mode and normal or limited service is available, the DMT
can be forcibly switched to non-priority mode by manual at any time if user wants tochange the mode.
3.2.2.3

Background scanninga. The purpose of the background scanning procedure is to inform the DMT about the possibility toswitch to the other mode if the currently selected mode would be non-priority mode.
b. General procedures of background scanning may be considered as following steps;
1) searching for coverage of the air interface in the non-active mode2) checking the stability of coverage and the switching conditions if the coverage is identified.
3) inform checking result to the automatic mode selection mechanism.
Note 1: The background scanning is performed without leaving the current active mode.
Note 2: The function of mode changing is not part of the background scanning. Mode changing
may be activated if necessary switching conditions would be satisfied at the automatic
mode selection mechanism.
Note 3: A criteria of a coverage stability could be the field strength by periodic RSSI
measurement of the DMT in order to save battery power. The other criteria may be given
by a certain protection mechanism to prevent frequent switching operation between thetwo modes.
3.3 Engineering considerations
Followings are identified issues to be taken in to account for a complete DMT specification:
3.3.1 Excessive mode switching
For automatic mode switching, there is a need to prevent excessive mode switching between the two
air interfaces.
This frequent switching may cause followings when moving on the border between PHS and GSM
coverage.
a. degradation of serviceability of the terminal (service interruption during the mode switching)b. excessive battery drain

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6

c. network overload by excessive attach/detach signaling(GSM only)
Note : The excessive mode switching is occurred by background scanning due to the principleof the usage for priority coverage when possible.
To avoid the frequent mode switching, a certain control mechanism may be given into thebackground scan processing by manufactures.
3.3.2

Missed paging

Paging may be missed by a type 2 DMT when it is scanning the other air interface.
Paging being missed by the DMT will force the networks to take actions as if the terminal is notreachable even if it is present in the coverage.
3.3.3

Handover between air interfaces

For earlier implementation of DMT, any handover function between PHS part and GSM part in a
DMT is not considered in dual mode operation.
3.3.4

Call Forwarding

If a DMT is not reachable for incoming calls in one mode, call forwarding supplementary services
can be activated to the other mode by the network. But this capability may be out of scope of the
DMT specification.

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7

4.

Principles for type approval for DMTs

4.1 Telephony requirements
For DMTs the technical specifications related to PHS and GSM telephony requirements can always
be applied independently, therefore the type approval testings are also assumed to be performed
independently in the respective parts of the DMT.
The basic testing principle is as follows:a. when operating in PHS mode, the Adaptive Differential Pulse Code Modulation (ADPCM)
codec is used and the requirements of RCR TR-T2 [2] applies.
b. when operating in GSM mode TBR 9 [7] (phase 1) or TBR 20 [8] (phase 2) applies.
4 .2 Spectrum protection requirements
The coexistence criteria for DMTs are presumed to be no more strict than those of PHS and GSM
single mode terminal, which are already conformed by existing GSM and PHS specifications.
In this section, potential spectrum protection problems and testing issues regarding DMTs are
considered.
4.2.1

Testing philosophy

It is the basic testing philosophy that each physical layer of air interface shall be tested separately
according to each specifications. Some additional tests will be considered corresponding tocharacteristics and behavior of different types of terminals;
a. Type 1 DMT
There is no additional spectrum protection problem over those of a single mode PHS or GSM
terminal because this terminal activates only one transmitter or receiver at a time.
b. Type 2 DMT and type 3 DMT- As the relating configurations is the same as a type 1 terminal, the same test philosophy will
apply to type 2 and type 3 terminals.
- If the background scanning is supported in the terminal, there may be a potential of loss ofspectrum efficiency in the modes. The additional testing requirements will be studied
further.
4.2.2

Testing requirements

The following items are typical spurious emissions to be taken into account and detailed
requirements are summarized in Table 2;a.
Emission due to modulationb.
Emission due to transmitter transientc.
Emission due to inter-modulationd.
Spurious emission when allocated a transmit channele.
Spurious emission when not allocated a transmit channel
For type 1 DMT the relevant technical specifications can always be applied independently.
For type 2 and type 3 DMT the relevant technical specifications can be applied independently but
for some modes of operation, degradation in fulfilling existing requirements have to be considered
as well as new requirements for new behaviors.

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8

Table 2 Analysis of PHS and GSM requirements
Parameters

PHS
reference
Emission due to RCR STD-28 [1],modulation
subclause 3.4.2.3
Adjacent channel power
Emission due to RCR STD-28[1],transmittersubclause 3.4.2.5 Carriertransient
off leakage power( There is no properly partin PHS reference. To becheck provable part.)
Spurious
RCR STD-28[1],emission whensubclause 3.4.2.6
allocated aTransmission spurioustransmit channel
Spurious
RCR STD-28[1],emission whensubclause 3.4.2.6
not allocated a
Conducted spurioustransmit channel component

GSM Phase 2
reference
ETS 300 577 [5] (GSM
05.05), subclause 4.2.1.
ETS 300 577 [5] (GSM
05.05), subclause 4.2.2.

Remark
The measurements are done
only in the PHS frequency
band, or in the GSM bands.
The measurements are done
only in the PHS frequency
band, or in the GSM band, as
in the previous requirement.

ETS 300 577 [5] (GSM
05.05), subclause 4.3.3.

ETS 300 577 [5] (GSM
05.05), subclause 4.3.3.

D-DT1.00-01-TS

9

5. References
[1]
[2]
[3]
[4]
[5]
[6]
[7]
[8]

[9]

ARIB Standard RCR STD-28 Personal Handy-Phone System
RCR TR-T2 ARIB Technical Report : Test Items and Conditions for Private Personal
Station Compatibility Confirmation (Version 1.0)
A-GN-1.00-TS : PHS MoU document “Glossary and specific PHS abbreviations”
ETS300 535: “Digital cellular telecommunications system (Phase 2); Functions related to
Mobile Station (MS) in idle mode (GSM 03.22)”.
ETS300 577: “Digital cellular telecommunications system (Phase 2):Radio transmission
and reception (GSM 05.05)”.
ETS300 607: “Digital cellular telecommunication system (Phase 2):Mobile Station (MS)conformance specification; (GSM 11.10)”.
TBR 9: “European digital cellular telecommunications system; Attachment requirements
for Global System for Mobile communications (GSM) mobile stations; Telephony”.
TBR 20: “European digital cellular telecommunications system (Phase 2):Attachment
requirements for Global System for Mobile communications (GSM) mobile stations;
Telephony”.
ETR 100: “European digital cellular telecommunications system (Phase 2):Abbreviations
and acronyms (GSM 01.04)”.

6. Abbreviations and Terminology
6.1

Abbreviations

Glossary and specific PHS abbreviations can be found in A-GN-1.00-TS [3]Definition and specific GSM abbreviations may be found in ETR 100 [9].
For the purposes of this document, the following abbreviations apply:
ADPCM
BS
CS
DMT
GSM
ISDN
MS
PHS
PLMN
RSSI
SIM

D-DT1.00-01-TS

Adaptive Differential Pulse Code Modulation
Base Station
Cell Station
Dual Mode Terminal
Global System for Mobile communications
Integrated Services Digital Network
Mobile Station
Personal Handy-phone System
Public Land Mobile Network
Received Signal Strength Indicator
Subscriber Identity Module

10

6.2

Terminology

PHS and GSM specifications often use different terminology for equivalent functions. Therefore,
this section clarify some of the vocabulary used in this document. Similar PHS and GSM definitions
are not necessarily strictly equivalent to use as general formulations sometimes. If dual mode
standards are to be produced in this document, a common terminology needs to be defined as shownin Table 3.
Strict GSM terminology can be found in GSM 03.22 (ETS 300 535 [4]).
The PHS terminology can be found in A-GN-1.00-TS [3].
active communication: A state, where a communication link has been established between the
DMT and a fixed part in either GSM or PHS mode.
active mode: GSM or PHS mode after being selected and switch on procedures for that mode being
performed.
background scanning: The process whereby the DMT attempts to identify the existence ofavailable networks in the other mode than the one it is in.
Dual Mode Terminal (DMT): A terminal comprising both PHS and GSM parts.
GSM: In the present document, the GSM part of a DMT can be GSM 900.
GSM coverage: The sum of all GSM Public Land Mobile Network (PLMN) coverage where theDMT has at least limited service.
mode selection: A DMT based procedure, whereby operating mode, PHS or GSM, is chosen.
mode: A basic DMT is in either of the two modes PHS and GSM. In GSM mode the DMT behaves
as a GSM Mobile Station (MS) and in PHS mode the DMT behaves as a PHS Personal Station(PS).
Note: The word PHS is used to refer to the PHS air interface or the access network related to the
PHS air interface.
The word GSM is used to refer to the GSM air interface and the related access network.

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11

Table 3 Comparison of PHS and GSM terminology as used with respect to DMTs
PHS term
Personal station(PS)

GSM term
Mobile station(MS)

Cell station(CS)

Base station(BS)

Paging area

Location area

D-DT1.00-01-TS

12

Explanation
The combination of mobile termination equipment, subscription
identity equipment and any required terminal equipment.
Often through this document the word "terminal" is used for thoseterms.
The physical equipment providing the elementary part ofcoverage.
The word "cell" is often used through this document for thecoverage area of a cell/base station.
A group of cells all of whose broadcast location identities are thesame.