Mobilegurufun Home Page

First Generation (TACS)       Go^
In the early 1980's, the UK government wanted to introduce competition in the Telecomms industry. They decided to award two licences to operate cellular networks in 1982. One of the licences was awarded to BT, which formed a company with Securicor. Telecom Securicor Cellular Radio Ltd was born, which traded under the name Cellnet. The other licence was offered by holding a competition from which Racal-Millicom was selected out of the five applicants. This company was a member of the Racal Telecom group and is now known as Vodafone. The two companies along with the government jointly decided the standard for the UK networks. They agreed to base the network standard on the north American standard Advanced Mobile Phone System (AMPS) and this lead to the UK standard Total Access Communications System (TACS). Cellnet and Vodafone launched their networks in January 1985 and this was three months ahead of their licence requirement. They both expanded their coverage to 90% population requirement in 1987, two years ahead of the licence requirement. This was mainly due to strong competition between the companies. In just over two years from launch each network was supporting 400,000 customers, and continued to grow at such a pace that each company nearly doubled in size each year. When Cellnet and Vodafone were initially licensed by the DTI, they imposed a condition, which meant neither company was allowed to sell directly to the customer. All products and services were offered via Service Providers who became responsible for setting customer contracts, billing, tariffs etc. This was done either directly by the Service Provider or via Dealers. The basic concept behind cellular radio are not complex, the area to be covered by the system is divided into a number of regular cells, and each cell has a radio base station positioned to give coverage to that cell. The mobile connects to the nearest cell with the strongest signal and is then passed to a neighbouring cell with a stronger signal when the original signal becomes weak. This allows freedom for the mobile to move from cell to cell provided there is coverage in between
Basic System Parameters:

Frequency Band:

890 - 905 Mhz mobile Tx .......TACS 600 Channels

935 - 950 Mhz base Tx

890 - 915 Mhz mobile Tx .......TACS 1000 Channels

935 - 960 Mhz base Tx

872 - 905 Mhz mobile Tx .......E-TACS 1320 Channels

917 - 950 Mhz base Tx

Channel Spacing:

25Khz (with 12.5khz offset)

Voice Modulation:

FM, 9.5 Khz peak deviation

Signalling:

8 Kbits/s with Manchester encoding

Signalling Modulation:

Direct FSK, 6.4 Khz deviation

Signalling Protection:

5/11 fold redundancy + BCH block code

Second Generation (GSM)       Go^
A committee at the conference of European Posts and Telecommunications Administrations (CEPT) conceived Pan-European Cellular Mobile Radio System in 1982. The committee aimed to achieve four main goals.

• Provision of cellular services, which provide more functionality than analogue networks.
• Provision of new capacity to alleviate capacity shortage in metropolitan analogue networks.
• To develop, through Pan European Co-operation, a pool of technological expertise which would enhance Europe's ability to compete with US and Japan.
• To forward the European Commission's goals of universal telecommunications standardisation and access in Europe thus opening up markets on the scale of the US.

A working party called Groupe Speciale Mobile was tasked with the development of the standards. The standard that has emerged from this group has become widely known as GSM. In 1989 GSM was transferred from CEPT to the European Telecommunications Standards Institute (ETSI). CEPT however continues to provide a forum for European telecommunications standardisation.

Development over the years lead to a digital system using Time Division Multiple Access (TDMA). This was known as Primary GSM (P-GSM), which was split between two operators Cellnet and Vodafone in the UK. In response to a perceived future demand for even more capacity, P-GSM spectrum was extended to form E-GSM. At a late stage in GSM development the existing technology was modified to meet the need for PCN networks. This is known as DCS 1800 and is mainly used by One2One and Orange in the UK. The DTI agreed to release more spectrum in the DCS 1800 range for dual-band operation in the UK. This allowed GSM 900 operators such as Cellnet and Vodafone to establish a system using both 900Mhz and 1800Mhz frequencies. This brought major advantages by offering additional network capacity, but required dual band handsets. However the DTI also increased spectrum available in the UK for the two DCS 1800 operators One2One and Orange. Short Message Service (SMS)

This is available in all of the digital systems such as GSM, GPRS, EDGE and UMTS. It is one of the early packet data type for transport of short text messages from the mobile to the network, and from the network to the mobile. The traditional SMS also includes Cell Broadcast, which is the ability for the network to transmit information to the mobile. SMS can also be used as a general-purpose bearer such as the WAP protocol. It is also integrated into larger value added services such as integrated messaging services, e-mail delivery and notification, and status messages. Wireless Application Protocol (WAP)

This is a collection of protocols and transport layers that allow mobile and portable communication devices such as Personal Digital Assistants (PDA's) to receive information over the airwaves similar to computer users obtaining information over the Internet. SMS data messages can be incorporated into WAP to provide different services. Also General Packet Radio Service (GPRS) can provide an ideal mechanism for WAP services. Current WAP mobile services are slow and restricted due to capacity limitations. Hence the success of WAP in mobile communication will depend on how it can be adapted to serve new emerging technologies. General Packet Radio Service (GPRS)

The European Telecommunications Standards Institute (ETSI) has developed GPRS technology to make data across the GSM network, fast and more attractive. This is still a technology under development and most of the UK operators are planning to upgrade their networks. GPRS can be much faster than other traffic on GSM but the exact speed a single user sees will be directly related to the total number of users in a particular cell. However most GPRS transactions will be short hence reducing any delays. GPRS is designed for the internet hence internet services such as File Transfer Protocol (FTP), Web browsing, Internet chat will be possible at very fast speeds. It will also be an ideal mechanism for WAP. The operators will benefit from new revenue generating streams requiring short exchanges of information like telematic type applications such as automatic tollbooths. Other uses can be to check your bank balance or to initiate a fund transfer to pay bills. The potential for GPRS is immense and is considered to be a step towards UMTS the next generation of mobile technology.

Basic System Parameters

Frequency Band for DCS 1800 (UK)

1710 - 1785 Mhz mobile Tx

1805 - 1880 Mhz base Tx

Channel Spacing

200Khz, 374 Carriers, 8/16 Users per carrier

Duplex Spacing

95 Mhz, Frequency Division Duplexing (FDD)

Signalling Modulation

Gausian Minimum Shift Keying (GMSK) modulation

Signalling

270 Kbits/s, Time Division Multiple Access (TDMA)

Digital Speech Coding

Regular Pulse Excitation, Linear Predictive Coder (RPE-LPC), 13Kb/s, 6.5kb/s & 12.2Kb/s

Enhanced Data Rates for Digital Evolution (EDGE)

This is a new modification to GSM incorporating a change to the physical layer. The main advantage is that it gives higher data rates up to 384 Kb/s.

Bluetooth

This is a technology specification for small form factor, low cost, short-range radio links between mobile PCs, mobile phones and other portable devices such as Personal Digital Assistants (PDA's) etc.

Universal Mobile Communication System (UMTS)       Go^
can offer mobile multimedia applications such as video conferencing, location based services and image downloads . UMTS will provide the platform for a wide variety of future applications that do not yet exist and is in many respects difficult to imagine. It will provide enhanced person-to-person communication with high quality images and video capabilities. Access to information will be improved by utilising higher data rate and new flexible communication capabilities. UMTS will not be launched onto the mass market in the same way as GSM, but is intended rather as a logical continuation of current technology. The continuing evolution of the second-generation systems will create new business opportunities for manufacturers and operators as well as content and application providers using these networks. The result will not be a dramatic increase in customer numbers but rather a gradual rise in individual client take-up. The best-known new feature of UMTS will be higher user bit rates with connections up to 384 Kbps for circuit switched data and up to 2 Mbps on packet switched data.

You can download this power point slide showing concept third generation handsets from leading manufacturers.

UMTS services

Messaging services such as SMS, e-mail, Voice-mail and Fax all combined into a single application.

Video and Image services providing Conferencing, Streaming, Image download.

Information services offering Cinema ticket reservation, Restaurant locations, Tour Guide.

E-Cash capabilities allowing downloading of e-cash into mobile, Checking Bank balance, and Performing real transactions.

Access to Corporate databases to find phone and address book, e-mail addresses, product information.

The main attraction to UMTS is that with a maximum 2Mbps capacity there is so much potential to create new services which is currently unimaginable. Basically all the UMTS operators are looking for a killer applications that will uplift sales in third generation mobile subscribers. So if you want to be the next Bill Gate then think of a killer application for UMTS.

Global Standard :: View Diagram

The UMTS activity is a global activity with many institutions from Europe, Asia, America and China being involved.

One of the first major milestones was the World Administrative Radio Conference (WARC) held in 1992. At this conference third generation spectrum was defined. In parallel to the WARC activities a number of third generation research and standardisation activities were undertaken throughout the world particularly in Europe, Japan and USA. The result of these activities has led to the creation of IMT2000, the family of standards for Third generation digital communications. UK Spectrum Auction

The auction held in the UK awarded five companies licence for 3G spectrum. The five winners and the amount they paid for the spectrum is listed below.

Licence A: Hutchinsons 3G (TIW) 4,384,700,000

Licence B: Vodafone 5,964,000,000

Licence C: O2 (Cellnet) 4,030,100,000

Licence D: T-Mobile (One2One) 4,003,600,000

Licence E: Orange 4,095,000,000

Looking at the amounts paid for these licences clearly shows the extent to which companies went to obtain a licence. The importance of this technology and the future potential it offered was far too great to risk not winning a licence. Basically the companies felt at the time, the survival of their company was at stake if they failed to win a licence. Since then circumstances in the industry has changed and the market believes the licences were bought at far too higher rate. However the future of the technology is still believed to be a prosperous one and hence all of the companies awarded licences in the UK are investing heavily in building their 3G networks. The services that will be initially offered will be an enhancement to 2G services and will grow depending upon customer growth and market demand. Hopefully some of the services discussed in this site will be developed

The following conditions are placed upon the UMTS license holder in the UK:

Terms Date of Issue: 9/05/2000

License Duration: 31/12/2021

Coverage Requirement: 80% Population by EOY 2007

Maximum EIRP/carrier: 62dBm

Maximum EIRP/MHz: 58 dBm

Global Roaming       Go^

For global roaming it is best to check with your network operator prior to travelling. Find out whether your network operator has a roaming partner in that country and the type of mobile needed to connect to that network. Also ask your network operator for details of call charges during roaming abroad, as there may be charges for receiving a call. There may be other charges specific to individual networks hence it is always best to check before travelling.

Second Generation spectrum in USA

Federal Communications Commission (FCC) in the USA split the designated spectrum into six duplex blocks. USA has been divided into 51 Major Trading Areas (MTA) and 493 Basic Trading Areas (BTA). An MTA is broadly equivalent in size to a state, whilst a BTA approximates to a large city. Using a process of auctioning, the FCC has granted 10 years licences to two operators in every MTA, and four operators in every BTA. MTA's have access to 3 x 15 Mhz duplex blocks, whilst BTA's have access to 3 x 5 Mhz duplex block.

Air Interfaces for Third Generation services:

USA plans to deploy EDGE, WCDMA and multi carrier CDMA in the existing bands used by second-generation systems.

Europe plans to use IMT-2000 Band for WCDMA and EDGE for GSM 1800 bands.

Asia is expected to utilise IMT-2000 Band for WCDMA and GSM 1800 band for EDGE.

Korea is expected to utilise IMT-2000 Band for WCDMA.

Japan plans to deploy IMT-2000 band for WCDMA.

UK Spectrum Allocation        Go^

Frequency assignment is the authorisation to use a frequency channel under specified condition. The conditions will include location, power level, modulation and bandwidth. The assignment by central body such as the RA allows close co-ordination, permitting reasonable frequency re-use across the UK.

First Generation Frequency Bands:

890 - 905 Mhz mobile Tx .......................TACS 600 Channels

935 - 950 Mhz base Tx

890 - 915 Mhz mobile Tx .......................TACS 1000 Channels

935 - 960 Mhz base Tx

872 - 905 Mhz mobile Tx .......................E-TACS 1320 Channels

917 - 950 Mhz base Tx

Second Generation (GSM) Frequency Bands

1710 - 1721.5 Mhz mobile Tx ..................Vodafone/Cellnet Shared equally

1805 - 1816.5 Mhz base Tx ....................(DCS 1800 PCN)

1721.5 - 1751.5 Mhz mobile Tx ...............One2One

1816.5 - 1846.5 Mhz base Tx .................(DCS 1800 PCN)

1751.5 - 1781.5 Mhz mobile Tx ...............Orange

1846.5 - 1876.5 Mhz base Tx .................(DCS 1800 PCN)

Third Generation (UMTS) Frequency Bands:

1920.3 - 1934.9 Mhz mobile Tx TIW ........(Hutchinson 3G) (3 x 5 Mhz bands)

2110.3 - 2124.9 Mhz base Tx .....................Frequency Division Duplex (FDD)

1915.0 - 1919.9 Mhz mobile/base Tx .......Time Division Duplex (TDD)

1934.9 - 1944.9 Mhz mobile Tx .................Cellnet (mmo2) (2 x 5 Mhz bands)

2124.9 - 2134.9 Mhz base Tx ....................FDD

1910.1 - 1915.0 Mhz mobile/base Tx .......TDD

1944.9 - 1959.7 Mhz mobile Tx .................Vodafone (3 x 5 Mhz bands)

2134.9 - 2149.7 Mhz base Tx ....................FDD only

1959.7- 199.7 Mhz mobile Tx ..................One2One (2 x 5 Mhz bands)

2149.7 - 2159.7 Mhz base Tx ....................FDD

1900.3 - 1905.2 Mhz mobile/base Tx .......TDD

1969.7 - 1979.7 Mhz mobile Tx .................Orange (2 x 5 Mhz bands)

2159.7 - 2169.7 Mhz base Tx .....................FDD

1905.2 - 1910.1 Mhz mobile/base Tx .......TDD

The GSM Architecture       Go^
consists of three major sub-systems. These are Base Station Sub-System (BSS) that provides the air interface for Mobile Stations (MS), Network Sub-System (NSS) that connects calls between users, and Operation Sub-System (OSS) that allows remote monitoring and management of network.

SIM - Subscriber IdentityModule, ME - Mobile Equipment, BTS - Base Transceiver Station, BSC - Base Station Controller, TCU - Transcoder Unit, MSC - Mobile Switching Centre, PSTN - Public Switched Telephone Network, HLR - Home Location Register, VLR - Visitor Location Register, AUC - Authentication Centre, EIR - Equipment Identity Register, OMC - Operations & Maintenance Centre, OMC-R - OMC devoted to BSS, OMC-S - OMC devoted to NSS. Base Station Sub-system (BSS)

The Base Station function is divided into two main functional elements, the Base Station Controller (BSC) which also includes the Transcoder Unit (TCU), and the Base Transceiver System (BTS).

The BSC can control several BTS units. Each BTS will consist of a number of transceivers (TRX) and will serve a cell or a number of cells. The BSC unit also performs transcoding functions to convert between 64Kbps channel rate used in the Switching System and the 16Kbps channel rate for GSM traffic. Network Switching Sub-system (NSS)

The switching system connects mobile subscribers to other mobile subscribers in the same network or to other networks. To perform this function a number of Mobile Switching Centres (MSC) are employed. However to connect to users on another network requires a Gateway MSC (GMSC) which provides interconnection between different networks.

Associated with the MSC are location registers and authentication functions that allow the network to locate and validate system users. There is one Home Location Register (HLR) and Authentication Centre (AUC). However, each MSC has a Visitor Location Register (VLR) associated with it. Operation Sub-System (OSS)

The OMC provides remote monitoring of the network performance and permits remote re-configuration and fault management activity as well as alarm and event monitoring.

Mobile Station (MS)

The MS comprises of Mobile Equipment (ME) and a Subscriber Identity Module (SIM). The ME contains the software and hardware to operate as a mobile radio terminal. The SIM in conjunction with the network Authentication Centre (AUC) validates the MS. UMTS Network Architecture

One of the requirements for the Release 99 Architecture is to support roaming and inter-operation with the GSM system, hence the GSM system appears as one of the components of the UMTS Release 99 Architecture.

USIM - UMTS Subscriber Identity Module, UE - User Equipment, Node B - UMTS Base Station, SRNC - Serving Radio Network Controller, DRNC - Drift Radio Network Controller, SGSN - Serving GPRS Support Node, GGSN - Gateway GPRS Support Node, PDN - Public Data Network, SIM - Subscriber Identity Module, ME - Mobile Equipment, BTS - Base Transceiver Station, BSC - Base Station Controller, MSC - Mobile Switching Centre, GMSC - Gateway Mobile Switching Centre, PSTN - Public Switched Telephone Network, HLR - Home Location Register, VLR - Visitor Location Register.

CS-Domain
This is the Circuit Switched domain that is traditionally known to provide services such as speech calls. The Core Network (CN) component that implements the CS services for UMTS is the 3G-MSC.
PS-Domain
This is the Packet Switched domain that is known to provide services such as IP Based traffic. The CN component that implements the PS services for UMTS is the 3G-SGSN.

UMTS Terrestrial Radio Access Network (UTRAN)

This consists of the Radio Network Controller (RNC) and the Node B. The UTRAN is responsible for functions that relate to access, radio mobility and resource utilisation. The Serving Radio Network Controller (SRNC) is responsible for the logical connection between the UE and the CN. The Drift Radio Network Controller (DRNC) provides additional radio resources for a UE that is in a dedicated connection and a soft-handover state. The Node B that is attached to the DRNC will provide the physical resource to the UE, and the information on the uplink and the downlink is routed towards the SRNC.

User Equipment (UE)

The radio terminal that the subscriber uses to receive service from the UTRAN is known as the UE. This will arrive in the form of PDA terminals and Handsets similar to current GSM mobiles. The UE's will be supporting multimode GSM, GPRS and UMTS services. They will be supporting multi-band GSM900, DCS1800 and PCS1900 systems. The capabilities of these User Equipments will vary hence the UTRAN will read UE capabilities during set-up.

Mobile Phones & Health       Go^
Over half the people in Britain have mobile phones. We use them in a wide variety of settings such as at work, at home, out and about, for convenience and security. They have become part of our way of life. Mobile phones are low power devices that transmit and receive radio waves. These connect each phone to a network of base stations, so that users can make and receive calls. Radio waves have been used for communication for over 100 years. But the speed with which mobile phones have become so widely used is unprecedented. This has led to public concern about their impact on health.

Independent Assessment
Radio waves emitted above certain levels can cause heating effects in the body. International guidelines seek to ensure that exposure is kept below that level. All mobile phones sold in the UK meet these guidelines. The balance of current research evidence suggests that exposure to radio waves below levels set out in international guidelines do not cause health problems for the general population. However, there is some evidence that changes in brain activity can occur below these guidelines, but isn't clear why. There are significant gaps in our scientific knowledge. This has led a group of independent experts (Commissioned by government and headed by Sir William Stewart) to recommend "a precautionary approach" to the use of mobile phones until more research findings become available. If you use a mobile phone, you can choose to minimise your exposure to radio waves. These are ways to do so: Keep your calls short Consider relative SAR values when buying a new phone.

Driving
Anything that distracts a driver increases the risk of accident, posing a threat to pedestrians, cyclists, passengers and other road users. You must be in proper control of your vehicle while you are driving. Any lack of concentration or momentary inattention may result in you being prosecuted. Even using a hands-free phone while driving will distract you.
Children and young people under 16
Mobile phones are very popular with young people and have obvious attractions for personal security and keeping in touch with others. Parents and young people should make their own informed choices about the use of mobile phones. The current balance of evidence does not show health problems caused by using mobile phones. However the research does show that using mobile phone affects brain activity. There are also significant gap in our scientific knowledge. Because the head and nervous system are still developing into the teenage years, the expert group considers that if there are any unrecognised health risks from mobile phone use, then children and young people might be more vulnerable than adults. The expert group has recommended that in line with precautionary approach, the widespread use of mobile phones by children (under the age of 16) should be discouraged for non-essential calls. In light of this recommendation the UK Chief Medical Officer strongly advise that where children and young people do use mobile phones, they should be encouraged to: Use mobile phones for essential calls only. Keep all calls short (talking for long periods prolongs exposure and should be discouraged) The UK CMO's recommend that if parents want to avoid their children being subject to any possible risk that might be identified in the future, the way to do so is to exercise their choice not to let their children use mobile phones.
At Work
Mobile phones are often used at work. They can have benefits for safety, efficiency and convenience of employers and staff. Employers have legal duties to protect the health and safety of their employees. The Health and Safety Executives advises employers that they should instruct staff not to use mobile phones while driving, or doing anything else where safety is important and their use might interfere with concentration. Where employers require staff to use mobile phone, and concerns about possible health risks are raised, employers could respond by, for example: Explaining that mobile phones operate within international guidelines Discussing with concerned staff ways to reduce mobile phone use.
In Hospitals and Aeroplanes
The radio signals emitted by mobile phone systems can interfere with sensitive electronic equipment. In hospitals, aeroplanes and other restricted areas observe the warning signs and switch off your mobile when required.
SAR Values
It is possible to measure how much radio wave energy your body receives from each model of mobile phone. This is called the Specific Absorption Rate (SAR). From 2001, there will be a European Standard method for measuring SAR. This information will be provided to consumers for each model of mobile phone sold in the UK from this time. Users may wish to take account of these relative SAR values when choosing a mobile phone. All models sold in the UK already meet international exposure guidelines.
Hands-free Kit
The level of effectiveness of hands-free kit to reduce SAR is still uncertain. Further research is being carried out to investigate SAR levels when using phones with hands-free kit and the results will be made available as soon as they are completed.
Base Stations & Health Base stations are radio transmitters and receivers, which form an essential link in mobile phone communications. They have antennas, mounted either on freestanding masts or on existing structures and buildings, which use radio signals similar to those used in TV and radio broadcasting. Calls pass through these antennas as people use mobile phones within their coverage areas and this coverage area is referred to as cells. Cells usually have a radius of several kilometres. However, more base stations are needed where mobile phone usage is high. Therefore in rural areas cells can have a radius of 10km, while in towns and cities their radius may be less than few hundred metres. They overlap at the edges to ensure that mobile phone users remain within range of a base station. Without sufficient base stations in the right locations, mobile phones will not work. But people who live or work close to where they are sited sometimes expresses concerns about health. Independent assessment and research A group of independent experts led by Sir William Stewart has investigated the possible health effects posed by mobile phone technology including base stations, on behalf of the Government. The group looked at recent research, took evidence from scientists, and listened to the views of the public at open meetings around the UK. Their report was published in May 2000. Their Conclusion was that: "The balance of evidence indicates that there is no general risk to the health of people living near base stations, on the basis that exposures are expected to be small fractions of guidelines". Gaps in scientific knowledge led the Stewart Group to recommend a precautionary approach to the use of mobile phones and the base stations until more research finding become available. They added that in some cases people's well being may be adversely affected by insensitive siting of base stations. Further research is now being set up to keep pace with developments in mobile phone technology. Base Stations on or near schools Although the exposure from base stations will be many times lower than from using a mobile phone, the Stewart Group acknowledged that there was some public concern about base stations located on or near schools. The pattern of radio waves emitted is generally even, but there is a zone within each cell where the concentration of waves will be slightly higher. The base station operator will be able to provide information about the pattern of radio wave emissions if a school or parents are concerned about the possibility that this zone includes a school or any part of its grounds. Within the overall distribution of radio waves from base station across its cell, there is a zone where the concentration is higher than elsewhere. At ground level, this zone is usually some distance from the base station. The radio waves within it are still far below the levels for safety specified in international guidelines.
National Audit Radio waves above a certain level can cause heating effects to the body. International guidelines have been set to keep exposure to radio waves below that level. Mobile phone network operators in the UK have agreed to comply with these international guidelines. Exposure to radio wave emissions from base stations has been calculated to be thousands of times lower than the maximum levels stipulated by the guidelines. Some independent measurements have already been made which show compliance. However starting from Autumn 2000, a comprehensive audit of base stations is being carried out by the Radio-communications Agency. Base stations will be measured to confirm their compliance with guidelines on emission levels, and the results will be freely available from the Agency. The audit begins with base stations on school premises. The information on these pages has been compiled from the guidance leaflets "Mobile Phones and Health" and "Mobile Phone Base Station and Health" which have been released by the Department of Health. The advice given in these leaflets is based on a report for the Government, published in May 2000, by a group of independent experts led by Sir William Stewart. The group looked at recent research, took evidence from scientists, and listened to the views of the public at open meetings around the UK. The Government is already putting some of its main recommendations into practice. On the advice of the Stewart Group further major research, funded by government and the mobile phone industry, is now being undertaken. For further information and up to date guidelines visit the Websites listed below.

• Department of Health www.doh.gov.uk/mobile.htm
• Report of the Stewart Group www.iegmp.org.uk
• Radiocommunications Agency (RA) www.radio.gov.uk
• World Health Organisation www.who.int

Mobile Handset      Go^
The main function of the SIM is in conjunction with the network, to authenticate the MS. The SIM is removable and stores details such as:

Authentication Key

International Mobile Station Identity (IMSI)

Cipher Key

Temporary Mobile Subscriber Identity (TMSI)

Location Area ID

List of carriers for cell selection.

The ME comprise of the software and hardware allowing it to operate as a mobile radio terminal. The ME will have a unique International Mobile Equipment Identity (IMEI), allowing it to be verified by the Equipment Identity Register (EIR).
A GSM MS has by definition a number of operational modes:

• No service
• Limited Service
• Idle Mode
• Dedicated Mode
No Service occurs when the MS can't find GSM coverage. A mobile that can't find a suitable cell may acquire any cell and offer a Limited service (Emergency call only). When a GSM mobile camps on a cell, it is said to be in idle mode. Once MS has accessed a cell and is communicating with the network, it is in dedicated mode.
MS Power capability
The power ratings for the mobile are measured at the antenna connector. The Tx power of the mobile depends upon how far it is away from the base station. Hence it can use any power between Max and Min power capability. Basically the further the mobile is from the base station the more power it will use up to it's maximum limit.


GSM 900

Class1: Max Tx Power 20W but no Min specified.

Class2: Max Tx Power 8W and Min Tx Power 3.2mW

Class3: Max Tx Power 5W and Min Tx Power 3.2mW

Class4: Max Tx Power 2W and Min Tx Power 3.2mW

Class5: Max Tx Power 0.8W and Min Tx Power 3.2mW

DCS 1800

Class1: Max Tx Power 1W and Min Tx Power 1mW

Class2: Max Tx Power 0.25W and Min Tx Power 1mW

Class3: Max Tx Power 4W and Min Tx Power 1mW

UMTS User Equipment (UE)
The Mobile Equipment (ME) is the radio terminal used for UMTS radio communication. The UMTS Subscriber Identity Module (USIM) is a smart card that holds the subscriber identity, performs authentication algorithms, and stores authentication and encryption keys including subscription information. The handsets will vary from data terminals such as PDA's to mobile equipments similar to one's currently used for GSM. However they will all offer higher data rates compared to current handsets.



^Go