TR 27.901
Report on Terminal Interfaces: an Overview
V5.0.0 (PDF)
2002/06 10 p.
V4.1.0
2002/03 10 p.
V3.1.0
2002/03 11 p.
- Rapporteur:
- Dr. Neal, Adrian
Content for TR 27.901 Word version: 5.0.0
1 Scope p. 5
The present document discusses external and internal interfaces of a terminal, with the exception of the radio and USIM interfaces. The focus of the study has been on external interfaces, to identify where existing industry standards can be used and whether there would be a need for specifications to be produced within 3GPP.
2 References p. 5
The following documents contain provisions which, through reference in this text, constitute provisions of the present document.
- References are either specific (identified by date of publication, edition number, version number, etc.) or non specific.
- For a specific reference, subsequent revisions do not apply.
- For a non-specific reference, the latest version applies. In the case of a reference to a 3GPP document (including a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same Release as the present document.
3 Definitions and abbreviations p. 5
3.1 Abbreviations p. 5
For the purposes of the present document, the following abbreviations apply:
AT Commands
ATtention Commands
EIA
Electronics Industry Association
FCC
Federal Communications Commission
IEC
International Electrotechnical Commission
IEEE
Institute of Electrical and Electronics Engineers
IR
Infrared
IrDA
Infrared Data Association
ISDN
Integrated Services Digital Network
ISO
International Standardisation Organization
ITU-T
International Telecommunications Union - Telecom sector
ME
Mobile Equipment
MT
Mobile Termination
RF
Radio Frequency
TA
Terminal Adaptation
TE
Terminal Equipment
TIA
Telecommunication Industry Association
UART
Universal Asynchronous Receiver and Transmitter
USB
Universal Serial Bus
USIM
Universal Subscriber Identity Module
4 Assumptions of the technical specification work for terminal interfaces p. 6
4.1 General p. 6
4.1.1 The 3GPP terminal model p. 6
The area of external and internal interfaces for 3GPP MEs have been studied and Figure 1 shows the model that has been used. The external interface, other than the radio and USIM interfaces, is the TE-MT/TA interface. An example of an internal interface is the TA-MT interface, as illustrated.
4.1.2 Requirements p. 6
There is a vast variety of market expectations, depending on end-users' and operators' demands and needs, and the 3GPP terminal design choice must be made under full influence from these market requirements.
The goal is to find a way to minimize the time-to-market of new, evolved interface solutions, at the same time allowing for the widest possible service diversity, that can be provided by a variety of terminal designs.
The success of 3GPP requires that an efficient and flexible approach is found to give a timely and dynamic development of many kinds of terminals, each type optimized relative to its own specific target of market requirements, while at the same time not imposing restrictions on the global circulation of terminals.
4.2 Conclusions p. 6
It has been concluded that 3GPP should not produce any technical specifications for terminal interfaces (neither external, i.e. MT/TA-TE, nor internal, e.g. MT-TA) other than the radio interface and the USIM interface. This includes optional as well as mandatory mechanical, electrical and logical specifications for interfaces. As an exception, optional protocols that are necessary for 3GPP terminals and that are not defined elsewhere could be standardized. One agreed example is AT commands.
Instead of specifying external interfaces in 3GPP, appropriate open standards should be used for external interfaces for 3GPP terminals. A list of potential examples of such interfaces is shown in Table 1. It should be noted that the list of interfaces in Table 1 is not exhaustive and that new examples are likely to be added in the future as technical development advances. It should also be noted that proprietary external interfaces may be used in the 3GPP terminals. It is then up to the manufacturer to handle the adoption to standard interfaces.
Since the terminal external interfaces (other than the radio interface, the USIM interface and AT commands), are out of scope of 3GPP, the SDOs can develop their own physical connector specification based on their market requirements. Such specifications should be optional to allow for other terminal interface options to exist on those markets.
4.2.1 AT-commands p. 7
One important aspect for 3GPP terminals is not being specified in any other specification forum, namely the AT commands. The AT commands are necessary for 3GPP terminals and should therefore be specified in 3GPP. AT commands can be commonly used as a common protocol specification, regardless of whether a wired or wireless connection (IR or RF) is used.
Most of the AT commands will be needed both in GSM and 3GPP. For this reason there is a need to have full access in 3GPP to the GSM defined AT commands.
5 Examples of external interfaces p. 7
Below some potential examples of external interface specifications are given.
| Interface Standard | Physical Media (connector) | Data Rate | Network Topology | Standard |
|---|---|---|---|---|
| EIA-232F | Nine wires | Up to 115 kbps | Point to point | TIA/EIA-232-F UART (Intel 8251A Industry Standard) |
| EPP Enhanced Parallel Port | IEEE 1284 -connector with 25 or 36 wires | Up to 1,5 Mbps | Point to point | IEEE Std 1284-1994 |
| ISDN S-Interface | Eight wires | 2X64 kbps + 16 kbps | Point to point | ISO/IEC 8877:1992 ITU-T Recommendation I.430 |
| IEEE 802.3 Ethernet | Four wires | 10 Mbps | Multimaster | ISO/IEC 8877:1992 IEEE Std. 802.3 1998 Edition |
| USB | Four wires (USB Connector) | Up to 12 Mbps | Master to slave devices | USB Specification 1.1 |
| IEEE 1394 | Four wires (iLink connector) | 100 Mbps - 400 Mbps | Multimaster | IEEE Std. 1394 - 1995 |
| IrDA-SIR | Infra red transceiver (line of sight) | Up to 115 kbps | Point to point(s) | Infrared Data Association Serial Infrared Physical Layer Specification v1.3 |
| IrDA-MIR | Infra red transceiver (line of sight) | Up to 1 Mbps | Point to point(s) | Infrared Data Association Serial Infrared Physical Layer Specification v1.3 |
| IrDA-FIR | Infra red transceiver (line of sight) | Up to 4 Mbps | Point to point(s) | Infrared Data Association Serial Infrared Physical Layer Specification v1.3 |
| 802.11 - IR | Infra red transceiver (diffused IR) | Up to 2 Mbps | Multimaster | IEEE Std 802.11-1997 |
| 802.11-FHSS | Frequency-Hopping Spread Spectrum RF | Up to 2 Mbps | Multimaster | IEEE Std 802.11-1997 |
| 802.11- DSSS | Direct Sequence Spread Spectrum RF | Up to 2 Mbps | Multimaster | IEEE Std 802.11-1997 |
| Bluetooth | Frequency-Hopping Spread Spectrum RF | 721 kbs + 57,6 kbs or 2x432,6 kbs | Point to point(s) | Bluetooth Specification 1.0 |
$ Change History p. 8
