Nokia’s vision for a service platform supporting high-speed data
applications
EDGE
The business of wireless data is expected to grow in the region of
100-200 per cent per annum and the mobile communications industry
agrees that wireless data services will form the foundation for
future business. The enormous success of short messaging in many
countries proves that people accept the benefits of non-voice
services.We are now facing the introduction of Wireless Application
Protocol (WAP) as well as the higher transmission speeds of High
Speed Circuit Switched Data (HSCSD), soon to be joined by the
convenience of "always on-line" direct internet connections with
General Packet Radio Service (GPRS). These standards will enable
greater sophistication as end-user services move towards personal
multimedia. A new technology, Enhanced Data Rates for GSM Evolution
(EDGE) will be introduced to boost network capacity and data rates
of both circuit switching (HSCSD) and packet switching (GPRS), to
meet the demands of wireless multimedia applications and mass
market deployment.Many wireless data applications today can be
implemented with 9.6kbit/s data. However, bandwidth-hungry fixed
line data applications - web browsing, access to corporate data
bases, and so on - would benefit from higher transmission speeds
when used over the mobile network. HSCSD will significantly improve
performance, especially for time-critical applications. GPRS will
enable cost-effective wireless access to applications that rely
upon data bursts, adding packet switching to GSM with a
packet-based air interface on top of the current circuit switched
mode of operation. GPRS will provide the connectivity needed in
packet-switched data networks such as the Internet.EDGE, a new
radio interface technology with enhanced modulation, increases the
HSCSD and GPRS data rates by up to three fold. EDGE modulation will
increase the data throughput provided by the packet switched
service even over 400kbit/s per carrier. Similarly, the data rates
of circuit switched data can be increased, or existing data rates
can be achieved using fewer timeslots, saving capacity.
Accordingly, these higher speed data services are referred to as
EGPRS (Enhanced GPRS) and ECSD (Enhanced Circuit Switched
Data).EDGE, expected to be deployed in 2000-2001, is a major
improvement in GSM phase 2+. As a modification to existing GSM
networks, EDGE does not require new network elements. EDGE is
especially attractive to GSM 900, GSM 1800 and GSM 1900 operators
that do not have a licence for UMTS, but still wish to offer
competitive personal multimedia applications utilising the existing
band allocation. Also, EDGE can co-exist with UMTS, for instance to
provide high-speed services for wide-area coverage while UMTS is
deployed in urban hot spots.In the US, EDGE is part of the IS-136
high-speed concept which is one of the third generation RTT (Radio
Transmission Technology) proposals from TR45. EDGE will be also
standardised in the US which makes it possible to achieve a global
mobile radio system with many services characteristic to third
generation systems.Nokia is dedicated to supporting GSM operators
with wireless data solutions that help them create value in the
market place, both now and in the future. Wireless data is steady
evolution, not revolution. With Nokia's experience, the operator
starting today with wireless data can accumulate the skills and
know-how to build a strong market position, all the way to third
generation systems and the personal multimedia era. This White
Paper describes Nokia's understanding of the role and benefits of
EDGE as wireless data evolves towards personal
multimedia.
EDGEThe GSM standard is being developed to
support mobile services with radio interface data rates even over
400kbit/s. This work is being performed under the ETSI work item
EDGE (Enhanced Data Rates for GSM Evolution).The major change in
the GSM standard to support higher data rates is the new modulation
system, known as 8PSK (Phase Shift Keying). This will not replace
but rather co-exist with the existing GMSK (Gaussian Minimum Shift
Keying) modulation. With 8PSK, it is possible to provide higher
data rates with a somewhat reduced coverage, whereas GMSK will be
used as a robust mode for a wide area coverage.
EDGE brings more
speed and capacity when neededIn mature GSM markets, cellular
data penetration is forecast to increase exponentially during the
early 2000s. New wireless data applications and innovative terminal
types will generate completely new markets: aggressive GSM
operators can expect to obtain up to 30 per cent of their airtime
and revenue from wireless data by year 2000.HSCSD (High Speed
Circuit Switched Data) and GPRS (General Packet Radio Service),
introduced to GSM in 1998 and 1999 respectively, will enable
cellular operators to offer higher than 9.6kbit/s data rates to
their subscribers for new data applications.Cellular operators that
have invested in HSCSD and GPRS expect to be able to offer higher
data rates without building too many new sites. The ECSD (Enhanced
Circuit Switched Data) and EGPRS (Enhanced General Packet Radio
System) solutions offer data services comparable to 3rd generation
levels with considerably fewer radio resources than in standard
GSM. This means that EDGE TRXs (transceivers) carry more data per
time slot, decreasing the need for new TRXs/frequencies. In
addition, end user response times decrease, ensuring good service
levels as data usage increases.It could be possible for EDGE Phase
2 to provide a voice service using AMR (Adaptive Multirate Codec)
type of solution. EDGE TRXs would then be capable of carrying
multiple speech calls per time slot, increasing voice capacity.
Also, high quality codecs, e.g 32kbit/s would be feasible. EDGE as
a voice solution looks especially interesting for indoor systems
because of its scalable capacity.
EDGE boosts data ratesThe
Phase 1 EDGE standard, scheduled to be complete in the third
quarter of 1999, will contain both EGPRS and ECSD services. EGPRS
will be based on the footprint of GPRS, whereas ECSD will enhance
the data rates of HSCSD. It is expected that packet data will
dominate circuit switched data in future GSM data networks, calling
for EGPRS solutions with high flexibility and spectral efficiency.
Also, the high data rate real time services provided with ECSD are
seen as important for applications such as video retrieval and
video telephony.EDGE will provide significantly higher data rates
on the current 200kHz GSM carrier. The data rates being specified
by ETSI would bring ECSD rates up to 38.4kbit/s/timeslot and EGPRS
rates up to 60kbit/s/ timeslot. The data throughput per carrier
increases even over 400kbit/s. For ECSD, it is possible to support
a 64kbit/s real time service with a low bit error ratio (BER) by
allocating two time slots of 32 kbit/s each. The enhanced
modulation will adapt to radio circumstances and hence offer the
highest data rates in good propagation conditions, whilst ensuring
wider area coverage at lower data speeds per timeslot.
EDGE
complements UMTSEDGE will allow operators without a UMTS
(Universal Mobile Telephone System) licence stay competitive in
wireless data markets. However, UMTS operators can also use EDGE
for gradual rollout of high-speed data services and for wide area
coverage where UMTS would be used for urban areas.
EDGE builds on
existing GSM networkDue to the new air interface modulation and
the greatly increased data rates, some software and hardware
changes will be required to make a network EDGE capable and new
mobile terminals are required for enhanced services. However, EDGE
will not require any new network elements and will be able to
support older mobile terminals with GMSK modulation.
EDGE data
applicationsWith EDGE, GSM goes personal multimedia. EDGE will
boost all existing circuit and packet-switched services and enable
completely new high-speed data applications.
Enhanced General
Packet Radio Service (EGPRS)The dominant data networking
protocol, on which most data network applications are running, is
TCP/IP, the Internet Protocol. All web applications are run on some
form of TCP/IP, which is by nature a protocol family for packet
switched networks. This means that (E)GPRS is an ideal bearer for
any packet switched application such as an Internet connection.
From the end user's point of view, the (E)GPRS network is an
Internet sub-network that has wireless access. Internet addressing
is used and Internet services can be accessed. A new number, the IP
address number, is introduced with the telephone number. From the
Internet's point of view, the (E)GPRS network is just one
sub-network among many others.Typical EGPRS applications are:Online
EmailWebEnhanced short messagesWireless imaging with instant
picturesVideo servicesDocument and information
sharingSurveillanceVoice over InternetBroadcasting
Enhanced
Circuit Switched Data (ECSD)Some applications, such as fax and
video, require a transparent service (constant bit rates), while
other applications (the web, e-mail) can work well with
non-transparent services. Typical ECSD applications are:E-mail
download and uploadBandwidth-secure mobile high speed LAN
accessFile transferVertical applications such as batch-type field
sales information or document transferReal-time applications
demanding a constant bit rate and transmission delayTime-critical
wireless imagingMobile videophonyVideo on demandLive video
streaming
Market potentialGradually, non-voice services will
account for one third or more of GSM traffic and revenues. This
will not happen overnight, however, as wireless data is an
evolution, not a revolution. Thus a step-by-step approach to
educating the market and introducing more sophisticated services is
vital. EDGE provides a boost to data speeds using the existing GSM
network, allowing the operator to offer personal multimedia
applications before the introduction of UMTS. The time between EDGE
and UMTS introduction clearly improves the business case for UMTS
and may prove to be instrumental in gaining a long-term advantage
over competitors.As wireless data becomes available to all
subscribers and they demand a full set of high-speed services and
shorter response times, EDGE will provide an operator with a
competitive advantage. EDGE also enables data capacity to be
deployed when and where demand dictates, minimising the investment
required.
Added benefits with EDGEFor the
operatorMigration to wireless multimedia servicesThe
operator can increase data revenues by offering attractive new
types applications to end users.
Improved customer
satisfactionIncreased data capacity and higher data throughput
will decrease response times for all data services, thus keeping
end users satisfied and connected.
Possibility of early market
deployment of third generation type applicationsEDGE networks
are expected to emerge in year 2001, when mature markets are likely
to start demanding multimedia applications.
Quick network
implementationEDGE will not require new network elements and
EDGE capability can be introduced gradually to the
network.
Optimised network investment as GSM
enhancementFlexible data capacity deployment where the demand
is.
For the end userImproved quality of
serviceIncreased data capacity and higher data throughput will
decrease response times for all data services, thus keeping end
users satisfied and connected.
Personal multimedia
servicesAttractive new types of applications and terminals will
become available.
Potentially lower price per bitLower cost
of data capacity for high-speed data applications gives the
operator flexibility in pricing.
ConclusionsEDGE will provide
the solution for operators wanting to offer personal multimedia
services early and who need to increase the data capacity in their
GSM network prior to UMTS deployment. EDGE is especially valuable
for operators that do not deploy UMTS.EDGE will not replace
existing investments or services but will upgrade them to a highly
competitive level through gradual investment.EDGE rollout can
satisfy increased data demand and produce increased revenues by
first launching EDGE service in urban and office environments for
business users and then providing wider area coverage as private
usage takes off.
( Nokia 1999