6651_motdoc

7/31/2019 6651_MotDoc

1/7

WHITE PAPER

Motorola ReachIncreasingVoice Capacity in GSM Networks

7/31/2019 6651_MotDoc

2/72 Increasing Voice Capacity in GSM Networks

Table of

ContentsEXECUTIVE SUMMARY .................................................................... ................

OVERVIEW: THE DEMAND FOR ENHANCED NETWORK CAPACITIES ........

CAPACITY, EFFICIENCY ................................................................................

OPTIONS FOR ENHANCING GSM CAPACITIES ..............................................

INTEGRATED MULTI-LAYER RESOURCE MANAGEMENT .......................

SYNTHESIZER FREQUENCY HOPPING (SFH) ............................................

CONGESTION RELIEF .................................................................. ................

CONCENTRIC CELL ............................................................ ...........................

SINGLE BCCH ......................................................... .......................................

PUSH-TO-TALK OVER CELLULAR .......................................................... .....

GSM HALF RATE (HR) ................................................................. ................

ADAPTIVE MULTI RATE (AMR) ............................................................. .....

HOT SPOT ............................................................... .......................................

DUAL BAND............................................................ .......................................

CELL SPLITTING ................................................................. ...........................

IN-BUILDING........................................................... .......................................

FUTURE TECHNOLOGIES ................................................................. ................

CONCLUSION ............................................................. .......................................

ECUTIVE SUMMARY

his document provides an

verview of the technologies

vailable to enhance the capacity

nd efficiency of GSM networks.

7/31/2019 6651_MotDoc


OVERVIEW: THE DEMAND FOR ENHANCED

NETWORK CAPACITIES

Research conducted across 411 of the worlds key

mobile markets (including the US, UK, Germany,

Egypt, the Philippines, Japan and Sweden), indicatesthat customers are using their mobile devices more.

In the last year, Minutes of Use (MoU) have increased

by 10 percent. Key country highlights of average

monthly phone usage per subscriber include: the US

(over 10 hours), Canada (six hours) and Israel (five

hours). Even in the markets where mobile phone use

is the lowest (Turkey and Poland) people on average

still access services for over an hour (74 minutes).

While increased service usage is traditionally a key

success indicator for service providers, analysis

of revenues contradicts this assumption. Average

Revenues per User (ARPUs) have declined 5 percent

in the last 12 months. So while people use their

phones more, theyre paying less to do so. Two

factors contribute to this phenomenon. The first

is that while data offerings present a significant

opportunity to increase returns, (with analysts like

Informa Telecom and Media suggesting that data

could account for 20 percent of service provider

income by 2010), data currently accounts for a

relatively low level of sales. In North America data

receipts average 5 percent of earnings, a figure

which climbs to 12 percent for both Latin America

and Europe the Middle East and Africa (EMEA)

and 15 percent for Asia2.

So while service providers build out their data

offerings, voice remains the leading source of

revenues for the immediate future. And this is

where the second problem arises: voice has

become a fiercely competitive service with price

used as a differentiating device to attract and re

customers. Furthermore, in an increasing numb

of markets service providers are also targeting fi

line customers with attractive voice packages

strategy that requires wireless services to comp

against lower cost established wire-line busines

Taking these issues as a whole, its becoming

increasingly important for service providers to

ensure that networks run efficiently to reduce

operating costs and, to optimize GSM capacities

to meet increased demand for voice minutes w

maintaining quality of service.

CAPACITY, EFFICIENCY

While efficiency and capacity are increasingly

important characteristics for networks, several

factors inhibit efforts to improve these benchma

These include cost concerns, the unavailability ospectrum, the difficulty of obtaining physical cel

sites and the inability to add new antennas. An

intermittent demand for capacity is also a comm

problem. This is where service providers may

experience a large influx of people for short peri

of time; examples include sporting events, festi

or concerts where large spikes in call volumes c

tax network capacities.

With its wealth of experience and expertise in th

GSM arena, Motorola can provide service provid

ers with several capacity generating3 techniques

ensure optimum network performance as part o

Motorola Reach GSM Portfolio. Each of the optiis designed to be cost efficient to deploy enhan

existing network investments. This said, its impo

to note that while most revisions can be achieve

via software upgrades or re-configurations, there

can be hardware expenditure involved.

Increasing Voice Capacity in GSM Network

1 Merrill Lynch, Global Wireless Matrix Q304 2005

2 Motorola Networks Business projections

3 The capacity gains discussed are approximations and are ultimately dependent upon operator configurationss

7/31/2019 6651_MotDoc


SYNTHESIZER FREQUENCY HOPPING (SFH)

SFH supports more efficient interference

averaging to enable use of a tighter frequency

plan and to support more carriers per cell within

set frequency allocation. The technique can crea

up to 80 percent more capacity and it can also b

complemented by other approaches to througho

improvements such as Concentric Cell and AMR

(Adaptive Multi Rate) as described below.

CONGESTION RELIEF

Congestion Relief is a software feature that

facilitates dynamic sharing of the traffic load

between adjacent cells. The technique permits

a more efficient configuration of existing resour

and does not require new carriers. Use of Conge

Relief can result in a 10 percent capacity increas

while greatly reducing congestion during peak

loading times by allowing higher then average

call volumes to be seamlessly managed.

OPTIONS FOR ENHANCING GSM CAPACITIES

INTELLIGENT MULTI-LAYER RESOURCE

MANAGEMENT

Multi-layer resource management (IMRM) is

designed to provide service providers with a means

to manage traffic across Multi-band and Multi-RAT

(Radio Access Technology) networks via a predictive

algorithm that spreads the capacity across multiple

radio resource layers. Its a technique that optimizes

radio resource utilization, network operation and

maintenance. IMRM provides service providers with

a means to define their network in layers, applying

preferences to each one to achieve optimal resource

utilization. The BSS is given a set of parameters for

the cell level and for external GSM/GPRS/UMTS

neighbors. This balances the traffic between each

layer in an active mode via a predictive algorithm.

The feature will incorporate and augment the current

micro cellular and band preference sorting. The

number of resource layers can include GSM 900

Micro, GSM 900 Macro, GSM 1800 Micro, GSM

1800 Macro, EGSM, GPRS and UMTS. Currently

available in Motorolas GSR 8 release.

FIGURE 1.Synthesizer Frequency Hopping (SFH)

7/31/2019 6651_MotDoc


CONCENTRIC CELL

Concentric Cell is a software-enabled feature that

allows greater frequency reuse within the inner

zone of a cell - allowing more carriers per cell with

a set frequency allocation. Frequencies within each

concentric cell are isolated to avoid interference with

the outer concentric circle. Concentric Cell offers a

10-30 percent increase in addition to the 80 percent

increase that SFH provides.

Single BCCH:

In multi-band networks, both bands (900/1800

respectively) can share the same control channel,

reducing the number of broadcast control channel

(BCCH) frequencies. A single low frequency reuse

BCCH layer is required, eliminating the need for a

2nd broadcast layer. This can release 20 frequencies

that can be applied in a much tighter reuse pattern

with six frequencies in a reuse group. Therefore,

an additional three or more carriers could be addedto each cell as TCH (Traffic Channel) carriers offer-

ing the potential to generate a 37 percent capacity

increase from the network.

PUSH-TO-TALK OVER CELLULAR (POC)

Capacity increases can be achieved by enhancing

the network with Motorolas Push-To-Talk functionality.

This requires that the network is GPRS compliant

and customers must be equipped with a PoC device.

Push-To-Talk utilizes VoIP and unlike a standard mobile

call does not require any dedicated circuit switched

connectivity. This in turn can free up capacity. PoC

can be easily integrated into an existing GPRSnetwork all thats required is the connection of

a Motorola PoC server to the data core. The simple

process ensures that the network can be upgraded

quickly Motorola has completed several installations

in just a three-day period. In addition to the capacity

increase, PoC can also help increase ARPU as data

service charges are incurred via usage.

GSM HALF RATE (HR)

GSM Half Rate (HR) offers enhanced capacity ov

the air interface - corresponding to the proportio

of mobiles within a coverage area that support H

technology. While the speech quality is considered

inferior to other speech codecs, GSM HR capab

mobiles are widely available due to the formats ea

introduction into standards and therefore its consid

a viable option for high density areas. GSM Half

is available on all current handset models.

ADAPTIVE MULTI RATE (AMR)

AMR is an end-to-end system solution for improv

ments in voice quality and network capacity bas

on European Telecommunications Standards

Institute (ETSI) specifications. ETSI AMR define

new air interface voice-coding (codec) standard

allows the selection of different voice codecs depe

on the quality of the radio environment. Motoro

AMR implementation supports quality voicecom

nications in poor radio environments. Examples inc

within corporate offices or urban buildings wher

dedicated in-building coverage has been provide

The technology is particularly attractiveto service

providers that wish to attract fixed-linesubscribe

in both commercial and domestic sectors. AMR als

improves voice quality across the entire network

by supporting high quality voice codecs in radio

environments that cannot support Enhanced Full R

Its also important to note that due to a more robus

codec, AMR can support a tighter reuse pattern. If

percent AMR penetration could be achieved servi

providers can expect up to a 70 percent capacity g

HOT SPOT

This technique requires the deployment of micro-c

in capacity hotspots. Frequencies can be reused

from the macro cell layer. Hot spot deployment

can provide a 10-30 percent capacity increase b

performance is limited by the number and dens

of hotspots deployed. The solution does require

hardware expenditure.

Capacity increases can be achieved

by enhancingthe network with

Motorolas Push-To-Talk functionality.

GSM PoC devices that

are already in use.

Inner

Marco

9

3

7/31/2019 6651_MotDoc


DUAL BAND

Dual Band describes the facility for GSM infrastructure

and handsets to work across both 900MHz and

1800MHz frequency bands. The capability to handover

between them provides major capacity gains up

to a 125 percent increase in call volumes can be

achieved, with additional hardware expenditures

and site management.

CELL SPLITTING

Cell Splitting is the conversion of a single cell into

multiple cells by portioning antennas into sectors

or creating additional cells within an existing cell.

The solution requires hardware expenditure and

more sites have to be managed, but it can return

a 100 percent capacity increase.

IN-BUILDING

To enhance coverage within buildings micro cells

can be installed. Another alternative is the use

of macro base station equipment and distributed

antenna systems. Both these solutions are hot-

spot type applications and can achieve capacity

improvements of 10-20 percent; there will be

installation costs as cables and equipment must

be fitted to ceiling voids etc. Also, the technology

requires hardware expenditure and more sites

to manage.

FUTURE TECHNIQUES

One promising solution for future capacity gains is

transmit diversity. Transmit diversity is defined asthe use of multiple transmit antennas to achieve

signal reliability. Its accomplished by separating at

least two transmit antennas by a predetermined

distance. Exact copies of the same signal are then

sent from the respective antennas, the signals

can be sent simultaneously or alternately from

each antennae. A mobile can detect both signals

and choose the strongest or, combine them. The

reliability is achieved via the probability that

simultaneous copies of the signal will not be

faded at the same time given different paths.

3GPP standards are being investigated to determthe feasibility of GERAN evolution. Mobile recei

diversity and techniques such as turbo coding a

16/32 QAM modulation may also be utilized in t

future. Its important to note that its still not cle

what will be standardized and what the market

uptake will be.

CONCLUSION

Motorola is committed to providing service prov

with the capabilities that they need to stay compe

through the development of technologies to sup

high capacity, cost effective network evolution aon-going management. This paper has provided

snapshot of the techniques and features availab

from Motorola demonstrating that whether its a

software upgrade or hardware addition, significa

capacity increases can be achieved with minima

cost and reduced disruption. For further inform

tion on Motorolas comprehensive network solu

please visit www.motorola.com/networkoperat

or contact your local Motorola representative.

Motorola is committed to providing

service providerswith the capabilities

that they need to stay competitive

7/31/2019 6651_MotDoc

7/7

Motorola, Inc.

www.motorola.com/networkoperators

The information in this publication is subject to change without notice. Motorola shall not be liable for technical or

editorial errors or omissions nor for any damages resulting from the use of this material. Each configuration tested

or described may or may not be the only available solution. This test is not a determination of product quality or

correctness, nor does it ensure compliance with any federal, state or local requirements. Motorola does not warrant

products other than its own strictly as stated in Motorolas product warranties. MOTOROLA and the Stylized M Logo

are registered in the US Patent & Trademark Office. Canopy is a trademark of Motorola, Inc. All other product orservice names are the property of their respective owners.

Motorola, Inc. 2006.

0206networksgms

6651_motdoc

Documents