Cellular Phone Technology Terms and Definitions
BANDWIDTH is a term commonly used by
internet service providers or ISPs (who usually supply less than
they claim) and their subscribers who complain about the lack of it! Basically,
bandwidth is the amount of data that can pass through a connection in a
given amount of time. Also referred to as the data transfer rate per
second – bits (bps), Kilobits (Kbps) and Megabits
(Mbps). Learn more about
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 is printed on a label on or inside the device (a phone's may be under the battery) and
also the box it came in. A phone IMEI can be found using the
*#06#; USB modem dashboards may
show the IMEI in Diagnostics.
MSISDN (Mobile Subscriber Integrated Services
Digital Network Number) This is a unique number that
identifies a GSM or UMTS mobile network SIM subscriber 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 cell phone.
(Subscriber Identity Module) This is the plastic 'smart card' that
most mobile phones, tablets or UMTS USB modems contain for connection to the
cellular mobile network that provided the card. Some Apple devices use a 52%
smaller Micro SIM or microSIM for 3G data transfer. A
normal SIM can be cut to fit a
microSIM slot, and adapters can be bought cheaply or made by hand for a microSIM
to work (data-only) in a
standard SIM phone or modem.
USSD (Unstructured Supplementary Service
USSD 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 by mobile network services.
GSM (Global System for Mobile
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 3GUMTS/WCDMA
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 speeds. Various definitions exist and the "G"
number has become a marketing ploy used by mobile internet providers to
exaggerate their performance claims.
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 some call 3G, 3.5G or 3.75G may actually be faster than what
claim as 4G which is capable in theory of 300 Mbps. '5G' may not be needed for
the foreseeable future.
Here's a 7-minute video 'lesson' explaining
how 1G evolved into 4G and the differences between 3G and 4G. Now a couple of
years old, the information is still current:
1G Analog cellular technology for voice and
limited data transmission
2G - Digital narrowband circuit data (TDMA,
CDMA) 9.6 -14.4 Kbps
2.5G - Packet data on a 2G network (GPRS) 20-40
Kpbs, EDGE - an evolution of GPRS
3G - Digital broadband packet data (3.1 Mbps CDMA; 500-700
Kbps UMTS, HSPA, HSPA+, WCDMA
3.5G - EDGE upgraded to HSPA 1-3 Mbps
and HSDPA 2-7.2 Mbps (peak 14.4 Mbps)
4G - Digital broadband packet data ALL IP
including VoIP; typical 3-5 Mbps (peak 100 Mbps) includes WiFi,
WiMAX and LTE, an evolution of UMTS with possible 300 Mbps
5G - not fully defined or in service, 100
Mbps to 1 Gbps and higher speeds.
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
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.
(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 theUniversal 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 - HSDPA(High-Speed Downlink Packet
Access) allowsup to 7.2 Mbps or 14.4 Mbps. HSDPA is 5 times faster than EDGE and
times faster than GPRS. Access is by an operator SIM inserted into a phone,
tablet, laptop or notebook computer, otherwise using a USB air card or dongle.
Access) and HSPA+ HSPA allows downloads up to 14 megabits per second
(Mbps) and uploads at 5.8 Mbps. HSPA optimises WCDMA radio bandwidth by
increasing the transmission rate, sharing channel transmission, shortening the
time between transmission intervals, and improving the modulation and amplitude
of the signal.
is faster and more efficient – up to 56 Mbps and peak uploads of 22 Mbps; it can
also operate on an all-Internet protocol (IP) architecture.
- Wi-Fi, WiMAX, LTE 10-100 Mbps;4G
provides a comprehensive and secure IP-based mobile broadband solution to laptop
computer wireless modems, smartphones, and other mobile devices. 25/26 MHz
(2.5/2.6 GHz) frequency bands are common in Europe and Asia, while 700 MHz is
used in much of the Americas.
The two main 4G technologies are WiMax and LTE.
From August 2011, Planet Online offered 4G in Laos with Mobile WiMax;
LaoTel and Beeline have announced 4G upgrades for early 2013.
South Korea and Singapore already have 4G LTE.
In reality, 4G is can be a marketing term for
faster-than-standard-3G systems, and for devices capable of between 7.2 and 21 Mbps
– if the operator is providing the service.
A 4G USB modem will not perform any better than a 3.6 Mbps model if actual
download speeds are below that due to network congestion or ISP throttling.
WiMAX is a long range system
covering many square kilometres and uses licensed or unlicensed spectrum to deliver
connection to a network, in most cases the Internet.
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 and can be included in 4G.
Click the image to see how LTE (Long Term
Evolution) compares to WiMax – as is offered by the major providers in the US.
5G - Gigabit per
second - for the future: >1 Gbps (not
actually offered by anyone)