Mobile Acronyms GSM 2G, 3G, 3.5G, 4G, GPRS, EDGE, UMTS,

Some Common Cellular Phone Technology Terms and Definitions

IMEI Number (International Mobile Equipment Identifier)
All mobile phones and modems have a unique 15-digit identifier (not serial or model number) known as an IMEI number which appears somewhere on the device (a phone's may be under the battery) and the box it came in; it can also be retrieved by using a software program or by keying in the IMEI retrieval code *#06#

MSISDN (Mobile Subscriber Integrated Services Digital Network Number)
This is a unique number that identifies a GSM or UMTS mobile network subscription number. MSISDN is the full telephone number including international code for the SIM card in a mobile or cell phone. e.g. Sending
*110# will retrieve the MSISDN for a Laos SIM number.

USSD (Unstructured Supplementary Service Data)
is a real-time or instant messaging phone services for use with all GSM networks. USSD messages are sent from a GSM mobile or 3G modem using an asterisk * followed by a numeric sequence and ended with a hash or pound sign #. e.g. *122# will get an almost immediate reply with the credit balance for a Lao mobile device. Different operators in other countries may use their own individual USSD codes.

USSD is also a menu option on a USB 3G modem user 'dashboard' and can be used to query account credit, data balance, account refill and receiving instant replies. Response time for interactive USSD-based services is usually much quicker than the SMS text message method which may also be used my mobile network services.

GSM (Global System for Mobile Communications) replaced the first generation analog mobile communication systems, beginning with what became known as 2G (second generation) and is continuously evolving. While 2G (GPRS/EDGE) is still current, the much faster 3G UMTS and 4G/LTE networks are available in many countries, with 5G and beyond as goals. See more below. GSM networks operate in several frequency ranges for 2G and 3G networks, mostly either 900 MHz or 1800 MHz bands. In countries like the USA and Canada where those bands were already allocated, 850 MHz and 1900 MHz bands were used instead. Many mobile phones are 'quad band' for use on all four bands worldwide. 4G frequency bands are 2.3 GHz, 2.5 GHz and 3.5 GHz (2300, 2500, 3500 MHz)

G preceded by a number stands for Generation and is related to data transmission speed. Various definitions exist and the "G" number has turned into more of a marketing ploy by mobile internet providers. Possible data speeds and those achieved in reality differ greatly. Many factors will affect performance and the time it takes to download a file from a server. Throttling by the operator, traffic density, upstream provider networks, server load and more. What someone calls 3G may actually be faster than what another claims as 4G.

Here's a 7 minute YouTube video 'lesson' explaining the evolution of 1G to 4G, and is well worth watching:


In summary:

GPRS (General Packet Radio Service)

A Global System for Mobile Communications (GSM) initiative to deliver high speed packet data services to mobile terminals. GPRS allows many users to share the same channel and allows users to stay virtually 'on line' all of the time; radio resources are used only when data is actually being transmitted or received. Call setup is almost instantaneous and users may be charged on the basis of actual data transmitted, rather than connection time. Sometimes defined as GSM Packet Radio Service.

EDGE (Enhanced Data rate for Global Evolution)

A technology (also known as GSM++) that allows GSM (see above) operators to use existing frequency bands to offer wireless multimedia IP-based services and applications at speeds of 384 kbps with a bit-rate of 48 kbps per timeslot and up to 69.2 kbps per timeslot under ideal radio conditions. (A more realistic theoretical limit is 59.2 kbps per timeslot). The 384 kbps prediction is from an International Telecommunication Union (ITU)-defined objective in the ITU2000 standard. EDGE is fully based on GSM and requires relatively small changes to network hardware and software. For example, EDGE uses the same time division multiple access (TDMA) frame structure, logic channel, and 200-kHz carrier bandwidth as today's GSM networks, allowing existing cell plans to remain intact. Formerly called Enhanced Data rate for GSM Evolution.

What that means in simple English is that when you connect to the internet via your mobile phone, if EDGE is available, sites should appear (data download to your phone) faster than just standard GPRS.

In theory EDGE is twice the speed of standard GPRS. You might see a small icon on your phone screen that indicates that GPRS and/or EDGE is operating. There's no need to add special settings to your connection.

3G (third generation wireless)

3G is an ITU specification for the third generation of mobile communications technology. (Analog cellular was the first generation; Digital PCS the second.) 3G uses the WCDMA (Wideband Code Division Multiple Access) also known as the Universal Mobile Telecommunications System or UMTS standard. Key features of 3G systems are a high degree of commonality of design worldwide, compatibility of services, use of small pocket devices with worldwide roaming capability, Internet and other multimedia applications, and a wide range of services and devices.

The main difference between 2.5G and 3G wireless is the rate at which data can be transferred. Planned rates are: 144 kbps or higher in high mobility (vehicular) traffic, 384 kbps for pedestrian traffic, and 2 Mbps or higher in fixed applications or for indoor traffic. The EDGE (Enhanced Data rates for Global Evolution) air interface was developed specifically to meet the bandwidth needs of 3G.

3.5G - HSPA (High-Speed Packet Access) offered by some mobile operators, requires a special modem, built into some notebooks and also available as a USB dongle. Speeds up to 3.6 Mbps.

HSDPA (High-Speed Downlink Packet Access) boosts speeds to as much as 7.2 Mbps or 14.4 Mbps.

HSDPA is five times faster than EDGE and ten times faster than GPRS.

4G - Wi-Fi, WiMAX, LTE 10-100 Mbps  (10 times faster than 2G); so-called 4G provides a comprehensive and secure IP-based mobile broadband solution to laptop computer wireless modems, smartphones, and other mobile devices. 25 MHz frequency.

The two main 4G technologies are WiMax and LTE. By August 2011, only Planet Online offered 4G in Laos with Mobile WiMax.
South Korea has had 4G LTE since July 2011.

In reality, 4G is being used more as a marketing ploy to promote 'faster' systems and devices capable of higher than 7.2 Mbps speeds, up to 21 Mbps, providing the operator is actually offering them. A higher speed modem will not perform any better than a 3.6 Mbps model if actual download speeds are below that due to network congestion or throttling.

WiMAX is a long range system which can cover many square kilometres and uses licensed or unlicensed spectrum to deliver connection to a network, in most cases the Internet. (To be expanded)

Wi-Fi uses unlicensed spectrum to provide access to a local network within 100 metres.
WiFi can be used to complement a WiMax installation by extending local coverage within a building. (To be expanded)

Click the image to see how LTE (Long Term Evolution) compares to WiMax currently offered in the US.

Compare 4G LTE with WiMax 

5G - Gigabit per second - for the future: 1+ Gbps

(information from multiple sources)

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