Eric L: The next article listed: Curious how accurate you feel this comparison is. Best. Chaz
A Comparison between GPRS and cdmaOne Packet Data
Wireless operators around the globe are launching or preparing to launch packet data services over mobile
networks. Deploying packet data is a cost-effective way for mobile carriers to balance the network resources
required to sufficiently meet the needs of the growing market for voice services and the potentially large mobile
data market. The path to high-speed packet data differs greatly, however, between GSM and cdmaOne
networks. GSM operators require a new data backbone, base station upgrades and new handsets to offer
packet data services. Packet data in cdmaOne networks is standard and was built into the IS-95 standard from
its inception. All cdmaOne handsets and base stations are packet data capable today, and the networks utilize
standard Internet protocol (IP) based equipment. GSM is circuit- based, requiring a new packet data backbone
and new handsets, the commercial launch of which has been delayed until early 2001.
In order to take advantage of higher speed packet data, the GSM and cdmaOne upgrade paths include higher
speed handsets, which will be commercially available within the next 12 to 18 months. The next major upgrade
for GSM is GPRS which is 2.5G, while the next major upgrade for cdmaOne is 1X, which is 3G. We will examine
some of the critical factors affecting an operator's ability to migrate to higher speed services and to implement a
packet backbone. One of the most critical factors is the forward and backward compatibility of the
handsets--the capability of an older handset to operate on an upgraded network and the capability of a newer
handset to operate on an older network. The commercial availability of the packet capable handsets is the
second crucial factor. The Second factor is the cost and ease of integration of the packet data network and the
ability for third parties to implement services on these data backbones to offer high-speed Internet services.
Defining the market
Currently, mobile data rates are low on both GSM at 9.6 kbps with Circuit Switched Data and cdmaOne 95A
networks at 14.4 kbps in either circuit or packet switched modes. These speeds are far lower than those
available to a typical user of a PSTN wire-line network. However, we are now entering a period that will see new
and faster non-voice mobile services. For example, anticipating an increased demand for data services, Korean
and Japanese operators SK Telecom, Hansol, DDI and IDO have already implemented commercial cdmaOne 95B
packet data at speeds of 64 kbps.
Packet data
Equipment
requirements
GSM CSD (Circuit
Switched Data)
GPRS
(General
PacketRadio
Service)
EDGE (Enhanced
Data rates for
GSM Evolution)
IMT-2000 CDMADirect
Spread (CDMA DS)
Handset
No packet data
capability
-Single-Mode
phones
New handsets
GPRS--
enabled
handsets will
work on GPRS
enabled
networks and
9.6Kbps on
GSM networks
using
CSD-Dual
Mode phones
New handsets
EDGE-- handsets
will work at up to
384Kbps on
EDGE enabled
networks on
GPRS enabled
networks and
9.6Kbps on GSM
networks using
CSD-Tri-Mode
phones
New handsets CDMA
DS handsets will work at
up to 2Mbps and only
on 3G
networks-Quad-Mode
phones
Infrastructure
No packet data
capability
New packet
overlay/
backbone
needed for
circuit
switched
network
Further backbone
modifications
required
New infrastructure roll
out with existing
interconnect
Technology
Platform
Current GSM
TDMATechnology
GSM TDMA
platform with
additional
packet overlay
Modulation
changes required
to GSM TDMA
platform
New CDMA
infrastructure
The GSM data evolution path will always require new network infrastructure and new phones. Every one of the
future GSM data services from GPRS to EDGE to WCDMA (and High Speed Circuit Switched Data and
Wireless Application Protocol) requires the purchase of a new mobile phone to take full advantage of the
enhanced functionality, but all handsets will still be able to operate on the GSM network, allowing voice and
CSD at 9.6Kbps. The GSM roadmap for handsets is not forward and backward compatible. This means that
GPRS handsets will not work on EDGE or 3G CDMA DS base stations. A GSM carrier must make new
investments in base stations for GPRS, EDGE and 3G CDMA DS, while the packet backbone may only need
minor modifications after deploying GPRS. GSM also requires the implementation of IP based network elements
to allow a packet overlay onto a circuit switched network. The links between the existing GSM network
infrastructure entities and the IP backbone are comprised of proprietary hardware such as the Gateway GPRS
Service Nodes (GGSNs) that link the Internet to the IP backbone. These are MODIFIED IP routers.
Using standard IP routers would have given network operators and corporate customers vendor choice,
interoperability, economies of scale with existing purchasing patterns and the like. The biggest issue with
GGSNs is that new pieces of equipment raise security concerns with IT departments. This can hinder the
deployment of a mobile data application due to the need for integration and testing. Since network operators are
interested in the data traffic, this barrier to the sale presents a challenge for the corporate work force.
Discussions with suppliers of both standard IP routers and GGSNs have indicated that a GGSN will typically
cost three to four times more than the equivalent IP router, presenting another sales barrier. Network operators
are likely to subsidize the GGSN element- perhaps even giving it away free of charge with a minimum number of
GPRS phone sales.
The use of the proprietary GGSNs in the GPRS solution also has other cost implications for network operators
and third party developers. GGSNs will not realize the same economies of scale of the Internet network elements
that the cdmaOne solution does. Corporations all over the world are implementing standard routers in their
corporate landline Intranets and for standard Internet access. IT departments are building knowledge and skills
with standard IP network equipment. The addition of a new version of a router -GGSNs-- will require IT
employees to learn new non-standard router configurations specific to each GGSN vendor. We believe that this
will hinder the implementation of GPRS in corporate environments.
The cdmaOne packet data implementation, on the other hand, utilizes standard routers, which are the same ones
used in the landline Internet. The same IT professionals working on a corporate landline Intranet could transfer
the same skills to a mobile Intranet based on cdmaOne. This will result in greater revenues for operators and
lower costs for corporations. Operators will not need to be integral in developing every application that is used
on its network, and corporations will require fewer resources to develop applications.
GPRS will also eventually require Mobile IP in order to offer full mobility within the Internet. Without Mobile IP,
the GPRS network will not be able to identify a node such as a portable computer that has a standard IP
address. For example, GPRS subscribers with portable computers will not be able to log into a corporate network
using GPRS alone. The GPRS network will require Mobile IP to allow the corporate network to authenticate the
IP address of the portable computer. Since Mobile IP requires more network resources, this may lead to a
reduction in the volume of data available on each packet as the transport layer information increases. The
implication is that GPRS networks will be less efficient than cdmaOne networks. cdmaOne uses Mobile IP as its
transport layer.
Packet Data
Equipment
requirements
95A
95B
IMT-2000
CDMAMulti-carrier
1X(MC 1X)
IMT-2000
CDMAMulti-carrier
3X(MC 3X)
Handset
Standard
95A handsets will work
on all future networks:
95B, 1X and 3Xat
14.4Kbps-Single-Mode
phone *
Standard
inchipsets 1999
95B handsets will
work on 95A
networks at
14.4Kbps and 95B,
1X and 3X systems
at speeds up to 114
Kbps-Single-Mode
phone
1X standard in
chipsets in 2001
1X handsets will work
on 95A networks at
14.4Kbps, 95B
Networks at speeds up
to 114 Kbps and 1X
and 3X networks at
speeds up to
307Kbps-Single-Mode
phone
New handsets
3X handsets will
work on 95A
networks at
14.4Kbps, 95B
networks at speeds
up to 114Kbps and
1X networks at
speeds up to 307
Kbps and 3X
networks at
2Mbps-Single-Mode
phone
Infrastructure
Standard
New software in
BSC (Base Station
Controller)
1X requires new
software in backbone
and new channel cards
at base station
Backbone
modificationsNew
channel cards at
base stations
Technology
Platform
CDMA
CDMA
CDMA
CDMA
cdmaOne is based on IP standards, giving it an inherent advantage over GPRS. Current cdmaOne phones have
the standard IP protocols built into the handset, and cdmaOne networks use IP addressing within the network
without the need for an additional IP layer being added to the packet transport layer. This allows for a high
degree of backward and forward hardware compatibility for network operators looking to implement new higher
speed data services and evolve to 3G, which is an IP-based standard.
Today's cdmaOne networks already incorporate an IP gateway referred to as the Inter-Working Function (IWF).
This is essentially a standard IP router built into the network, routing IP packets without the need for them to be
handled by an analog modem. The IWF receives information from the mobile phone in Point to Point Protocol
(PPP) format and assigns a temporary IP address for that session. Experts estimate the cost for rolling out a full
network upgrade for 45 million POPS from GSM to GPRS is about US $125 million. Adding packet data to a
CDMA network is far less expensive: less than $5 million dollars. cdmaOne phones and base stations already
have IP protocols built in. Having the IP gateway as a standard feature NOW therefore represents a significant
advantage to cdmaOne network operators. The cdmaOne configuration is based on existing corporate
infrastructure standards. Certain network infrastructure manufacturers have stated that their new cdmaOne
infrastructure allows the incorporation of ANY standard router from any manufacturer into the IWF. A standard
RADIUS server undertakes billing information and authentication in the network, and messaging is handled
using SMTP. Integrating high speed cdmaOne data in a corporate network will be much easier than with GPRS,
as the infrastructure of cdmaOne is based on what is considered to be standard corporate infrastructure
components. Since there is backward and forward compatibility in the cdmaOne handsets, any handset can
operate on any cdmaOne network, (assuming the same frequency or the use of multi-band phones) of that
cdmaOne network (95A, 95B or 1X) at the highest available speed possible by both the handset and network.
For example, 1X handset will be capable of 14.4 Kbps on a 95A network and 64 Kbps on a 95B network. A 95A
handset will operate on a 95A, 95B or a 1X network, but only at 14.4Kbps.
* Across the raw air link; assumes 8 concatenated channels. With GPRS, the figures also assume no error
correction on data transferred.
^ Indicates initial/ current support (4 slots for GPRS)
" The typical data rate available to an individual user
We can see from this analysis that the maximum theoretical speeds available over GPRS are in fact higher than
95B but less than 1x-but in initial commercial implementations we expect 95B to outperform GPRS. KT Freetel,
and Hansol in Korea, commercially launched 95B in 1999 while DDI and IDO of Japan launched commercial
service in 2000. Several, but not all, of the GPRS network infrastructure vendors are planning to support the
maximum eight channels in their technical implementations. GPRS has a disadvantage in that the initial GPRS
capable mobile terminals are expected to support only a maximum of four simultaneous channels. GPRS and
voice both use the same traffic channels, meaning that that both voice and data are competing for the same
resource. Network operators, wherever they are in the world, are reluctant to dedicate channels or assign
priority to data over voice. Because of real world limitations the typical bandwidth available to a GPRS user is
expected to be less than 30 kbps, similar to the wire-line data transfer rates in 1999 and below today's 95B.
EDGE has a maximum theoretical data rate of 384 kbps, but EDGE works in a similar way to GPRS in that this
would require all 8 timeslots-which is unlikely-- to be available to a single user who would also need to be given
priority over voice. As such, the theoretical maximum is once again an irrelevant figure to an end user. We
expect uses to get 114 kbps data rates.
We estimate that CDMA 1X will allow approximately 90% throughput of the implemented bandwidth to the
application layer and therefore offers a typical user rate of 130 kbps, five times the typical data rate available to
a GPRS user. It should be noted that the144 kbps rate is symmetrical.
Summary
From this analysis, we can see that the packet data design that is standardized in the network and handsets of
the cdmaOne standards technology facilitates easier and therefore less expensive packet data implementation
than GPRS from a network operator, handset, application developer and corporation's point of view. All
cdmaOne handsets are packet data capable and work on all implementations of cdmaOne networks. Phones do
however remain a significant barrier to the widespread uptake of higher speed data services on both GSM and
CDMA networks.
Any network operator who is facing the decision of which network to buy should consider the upgrade paths
of each network. GSM networks were not designed for packet data-- a GPRS upgrade adds this capability but at
a higher cost than cdmaOne. Also, the GPRS network is not based on standard IP network elements, which will
result in a more complicated integration than the cdmaOne packet data solution that was designed with
standard IP in the handsets and with standard IP elements in the network. These standard elements will follow
the cost curves of the Internet network elements. Additionally, GPRS and EDGE dedicate network resources to
data taking capacity away from the GSM voice network which could cause network congestion. CDMA is a
voice and data solution where voice and data share the same resources. 1x also increases data speeds to 144
kbps and doubles the voice capacity of current cdmaOne systems
By incorporating standard IP protocols and network IP routing, cdmaOne sensibly maximizes the leverage it
gains from the considerable economies of scale conferred by the Internet. This will allow cdmaOne carriers to
offer the equivalent Internet services as GPRS and EDGE operators with a lower overall investment in
equipment and human resources and without decreasing voice capacity. Network operators will more readily
find the skills to integrate equipment and develop services because the same IP elements are used on the
landline Internet.
Prepared by Warren Carley and Simon
Buckingham
Mobile Lifestreams Limited
9 The Broadway
Newbury, Berkshire
RG14 1AS, UK
Tel +44 7000 366366
Fax +44 7000 366367
simonb@mobilelifestreams.com
www.mobilelifestreams.com
Disclaimer
Mobile Lifestreams is a research and consulting company specializing in non-voice services. Mobile
Lifestreams Ltd uses its best efforts in the collection and preparation of the information included in the
enclosed report. It does not assume, and hereby disclaims, any liability for any loss or damage caused by errors
or omissions, whether such errors or omissions resulted from negligence, accident or other causes. Mobile
Lifestreams Ltd and its associates do not have stock positions or options in any of the companies discussed
herein. Mobile Lifestreams was paid to conduct this research. Mobile Lifestreams is the author and publisher of
"Data on GPRS" and "Data on 3G", independent industry research documents (See www.mobileGPRS.com and
www.mobile3G.com).
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