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Cellular technology has developed a long way since the first mobile phone systems were introduced. Since the beginnings of cellular technology in the 1970s and 1980s, many different mobile phone systems have been used, and currently a large variety of phone systems are in use now.
Originally a vast number of cellular systems were used when the first analogue cellular technologies were introduced. Many countries had their own cellular systems, making for a large number of different systems around the globe. With the introduction of GSM and the possibility of international roaming, the number of cellular systems that were deployed reduced. However the systems that were available underwent a number of developments enabling data to be sent, or increasing the rates at which data could be sent over the networks. The overall result is a bewildering number of different systems, each with its own advantages and disadvantages.
To try to summarise the different cellular telecommunications systems that have been used the table below has been compiled. It gives an overview of the different mobile phone systems or cellular technologies that are in use today and those that have been used over the years. Although not every cellular technology is included, those that have been more widely used are included.
|Mobile Phone System||Generation||Channel Spacing||Access Method||Comments|
Advanced Mobile Phone System, this analogue system was first developed and used in the USA.
Narrow band version of AMPS chiefly used in the USA and Israel based on a 10 kHz channel spacing. The aim was to conserve spectrum and thereby allow a larger number of users.
Analogue system developed by Motorola was originally used in the UK. Based around 900 MHz, this system spread world wide. After the system was first introduced, further channels were allocated to reduce congestion, in a standard known as Extended TACS or ETACS
Nordic Mobile Telephone. This analogue system was the first cellular technology to be widely used commercially being launched in 1979. It was used initially on 450 MHz and later at 900 MHz. It was used chiefly in Scandinavia but it was adopted by up to 30 other countries including Oman.
Nippon Telegraph and Telephone. This cellular technology was used in Japan in the 900 MHz frequency band with a 55 MHz transmit receive spacing. (A high capacity version known as HICAP was also developed).
The system adopted in West Germany (East Germany was separate at this time). It used a band in the region of 450 MHz along with a 10 MHz receive / transmit spacing.
Originally called Groupe Speciale Mobile, the initials later stood for Global System for Mobile communications. It was developed in Europe and first introduced in 1991. This cellular technology was originally used on frequencies around 900 MHz, but its use has been expanded to other bands including those around 1800 MHz, 1900 MHz and 850 MHz (the latter two are mainly used in North America). GSM is the most widely used cellular technology with over 2 billion subscriptions currently active.
|DCS 1800||2G||200 kHz||TDMA|
The original name for GSM used at 1800 MHz.
|PCS 1900||2G||200 kHz||TDMA|
The original name for GSM used at 1900 MHz.
Although it was originally known as US Digital Cellular (USDC) and was introduced in 1991. It is sometimes called North America Digital Cellular and also known by its standard number IS-54 that was later updated to standard IS136. It is a 2G digital system that was designed to operate alongside the AMPS system.
Pacific or Personal Digital Cellular. The system found only in Japan where it has gained very widespread use. It has many similarities with IS-54 although it uses a different speech coder and a 25 kHz bandwidth.
General Packet Radio Service. A data service that can be layered onto GSM. It uses packet switching instead of circuit switching to provide the required performance. Data rates of up to 115 kbps attainable.
|EDGE||2.5 / 3G||200 kHz||TDMA|
Enhanced Data rates for GSM Evolution. This cellular technology uses a different form of modulation (8PSK) and packet switching which is overlaid on top of GSM to provide the enhanced performance. Systems using the EDGE system may also be known as EGPRS systems.
This is the brand name for the cellular technology with the standard reference IS95. It was the first CDMA system to gain widespread use. The initial specification for the system was IS95A, but its performance was later upgraded under IS95B which the cdmaOne specification actually uses. Apart from voice it also carries data at rates up to 14.4 kbps for IS95A and under IS95B data rates of up to 115 kbps are supported.
|CDMA2000 1X||2.5G||1.25 MHz||CDMA|
This cellular technology supports both voice and data capabilities within a standard 1.25 MHz CDMA channel. CDMA2000 builds on cdmaOne to provide an evolution path to 3G. The system doubles the voice capacity of cdmaOne systems and also supports high-speed data services. Peak data rates of 153 kbps are currently achievable with figures of 307 kbps quoted for the future, and 614 kbps when two channels are used.
|CDMA2000 1xEV-DO||3G||1.25 MHz||CDMA|
The EV-DO stands for Evolution Data Only. This is an evolution of CDMA 2000 that is designed for data only use and its specification is IS 856. It provides peak data rate capability of over 2.45 Mbps on the forward or downlink , i.e. from the base station to the user. The aim of the system is to deliver a low cost per megabyte capability along with an always on connection costed on the data downloaded rather than connection time.
|CDMA2000 1xEV-DV||3G||1.25 MHz||CDMA|
This stands for Evolution Data and Voice. It is an evolution of CDMA2000 that can simultaneously transmit voice and data. The peak data rate is 3.1 Mbps on the forward link. The reverse link is very similar to CDMA2000 and is limited to 384 kbps. In view of the success of CDMA2000 1xEV-DO, it has never been deployed, although it reached an advanced stage of development.
|3G||5 MHz||CDMA / TDMA|
Universal Mobile Telecommunications System. Uses Wideband CDMA (W-CDMA) with one 5 MHz wide channel for both voice and data, providing data speeds up to 2 Mbps.
(HSDPA and HSUPA)
|3.5G||5 MHz||CDMA / TDMA|
High Speed Packet Access using High Speed Downlink Packet Access and High Speed Uplink Packet Access. HSPA provides for high speed packet data at speeds up to 14.4 Mbps in the downlink using packet data. The specifications were progressively released under Rel 4 to Rel 6 of the 3GPP specifications.
Time Division Synchronous CDMA. A cellular technology developed in China to establish their position on the cellular telecommunications arena. It uses the same bands for transmit and receive, allowing different time slots for base stations and mobiles to communicate. Unlike other 3G systems it uses only a time division duplex (TDD) system.
|LTE||3.99 / 4G||OFDMA|
The Long Term Evolution path for the UMTS / W-CDMA cellular technology. It provides broadband data throughputs and uses orthogonal frequency division multiplex (OFDM) as the modulation technique and Orthogonal Frequency Division Multiple Access as the access technique.
|UMB||3.99G / 4G||OFDMA|
Ultra-Mobile Broadband. This is the 3.99 / 4G evolution cellular technology for CDMA2000.
The different mobile phone systems and cellular technologies are always evolving to provide improved capabilities. Cellular operators need to look to increasing their ARPU (average revenue per user) and with revenues from voice alone falling, it is necessary to introduce new data services to improve revenues. As a result the different mobile phone systems and their associated cellular technologies will continue to evolve.