Evolution of Mobile Evolution of Mobile Communications Systems Communications Systems

11

UKUK--UbiNet UbiNet WorkshopWorkshop

London, 25 London, 25 -- 26 September 200326 September 2003

Evolution of Mobile Evolution of Mobile Communications Systems Communications Systems

John DunlopJohn DunlopMobile Communications GroupMobile Communications Group

University of StrathclydeUniversity of StrathclydeGlasgow, ScotlandGlasgow, Scotland

22

Outline of TalkOutline of Talk

Outline of the differences between wired and wireless Outline of the differences between wired and wireless communication systemscommunication systemsIntroduction the paradigm shift in wireless systemsIntroduction the paradigm shift in wireless systemsThe The InfostationInfostation ConceptConceptFuture service delivery optionsFuture service delivery optionsThe role of a Personal Distributed Environment (PDE) in The role of a Personal Distributed Environment (PDE) in evolving wireless networksevolving wireless networksConclusionsConclusions

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Radio EnvironmentRadio Environment

Mobile Communication Systems use Radio FrequenciesMobile Communication Systems use Radio FrequenciesRadio spectrum is a finite resource and the amount of Radio spectrum is a finite resource and the amount of spectrum available for mobile communications is spectrum available for mobile communications is strictly limitedstrictly limitedThe radio environment is subject to multipath The radio environment is subject to multipath propagation, shadow fading and interference and is not propagation, shadow fading and interference and is not therefore an ideal transmission mediumtherefore an ideal transmission mediumThe subscriber is able to move and this movement must The subscriber is able to move and this movement must be accommodated by the communications systembe accommodated by the communications system

44

Sharing of ResourcesSharing of Resources

A fixed amount of radio spectrum is allocated to mobile A fixed amount of radio spectrum is allocated to mobile communications systems.communications systems.This spectrum must be reThis spectrum must be re--used many times to used many times to accommodate the massive demands.accommodate the massive demands.ReRe--using radio frequencies causes interference.using radio frequencies causes interference.Cellular planning is designed to keep interference at Cellular planning is designed to keep interference at acceptable levels.acceptable levels.The next slide illustrates the main principle of frequency The next slide illustrates the main principle of frequency rere--use.use.

55

Cellular LayoutCellular Layout

f4f4

f5f5 f6f6

f1f1 f7f7

f3f3 f2f2f4f4

f5f5 f6f6

f1f1 f7f7

f3f3 f2f2

f4f4

f5f5 f6f6

f1f1 f7f7

f3f3 f2f2

f4f4

f5f5 f6f6

f1f1 f7f7

f3f3 f2f2

fixed networkfixed network MSCMSC

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Frequency reFrequency re--use anduse andInterferenceInterference

The capacity of the system can be increased only by reThe capacity of the system can be increased only by re--using the carrier frequencies more often (smaller cells)using the carrier frequencies more often (smaller cells)This increases interference and handover ratesThis increases interference and handover rates

77

Cellular Developments Cellular Developments (Europe)(Europe)

First Generation First Generation 19851985 (e.g. (e.g. AnalogueAnalogue TACS, 900 MHz)TACS, 900 MHz)•• Voice and limited data, no roaming, cell radius 30 kmVoice and limited data, no roaming, cell radius 30 km

Second Generation Second Generation 19921992 ((DigitalDigital GSM, 900/1800 MHz)GSM, 900/1800 MHz)•• Voice and circuit switched data (9.6 kb/s), international Voice and circuit switched data (9.6 kb/s), international

roaming, encryption, cell radius 5 roaming, encryption, cell radius 5 –– 10 km.10 km.Enhanced 2G (2G+) Enhanced 2G (2G+) 19951995•• SMS, AMR, GPRS (144kb/s), EDGE (384 kb/s)SMS, AMR, GPRS (144kb/s), EDGE (384 kb/s)

Third Generation Third Generation 20032003 ((Digital CDMADigital CDMA))•• Multimedia Services, cell radius 2.5 km, packet data 2.0 Multimedia Services, cell radius 2.5 km, packet data 2.0

Mb/s Mb/s

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Paradigm Shift in Mobile Paradigm Shift in Mobile CommunicationsCommunications

11stst GenerationGeneration

•• AnalogueAnalogue•• Circuit switchedCircuit switched•• Basic voice Basic voice

telephonytelephony•• Low capacityLow capacity•• Limited local Limited local

and regional and regional coveragecoverage

Beyond 3GBeyond 3G•• DigitalDigital•• Packet switchedPacket switched•• All IP based All IP based

(IPv6)(IPv6)•• More advanced More advanced

multimedia multimedia applicationsapplications

•• User in controlUser in control•• Flexible platform Flexible platform

of complementary of complementary access systemsaccess systems

•• High speed dataHigh speed data•• ImprovedImproved QoSQoS•• Global coverageGlobal coverage•• Global roamingGlobal roaming

22ndnd GenerationGeneration

•• DigitalDigital•• Circuit switchedCircuit switched•• Voice plus basic Voice plus basic

data applicationsdata applications•• Low data speedLow data speed•• Enhancements Enhancements

towardstowards•• packet packet

switchingswitching•• higher data higher data

ratesrates•• TransTrans--national national

and global and global roamingroaming

33rd rd GenerationGeneration

•• DigitalDigital•• Packet and circuit Packet and circuit

switchedswitched•• Data and Data and

multimedia multimedia applicationsapplications

•• Medium data Medium data ratesrates

•• Global coverageGlobal coverage•• Global roamingGlobal roaming

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Capacity IssuesCapacity IssuesUbiquitous communications and pervasive computing will cause Ubiquitous communications and pervasive computing will cause serious capacity problemsserious capacity problems

Typically 10Typically 1044 devices/kmdevices/km22 will require a capacity ofwill require a capacity of GbGb/s/km/s/km2 2

InternetInternet

Wireless AccessWireless AccessNetworksNetworks

mobile communicators (10mobile communicators (1099))

low level sensors (10low level sensors (101010))

semisemi--mobile laptops (10mobile laptops (1088))

Up to 75% of all computing Up to 75% of all computing devices will have wireless devices will have wireless

connectivityconnectivity

fixed PC/WS (?)fixed PC/WS (?)

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Limits of Existing SystemsLimits of Existing Systems2G Cellular2G Cellular•• cell cell ≈≈ 3 3 –– 10 km, BW 10 km, BW ≈≈ 5 MHz, modulation speed 5 MHz, modulation speed ≈≈ 0.2 0.2 –– 0.3 b/s/Hz0.3 b/s/Hz•• max capacity/kmmax capacity/km22 ≈≈ 100kb/s average, 1 Mb/s peak (packet)100kb/s average, 1 Mb/s peak (packet)•• 3 orders of magnitude out 3 orders of magnitude out

3G Cellular3G Cellular•• cell cell ≈≈ 2 2 –– 5 km, BW 5 km, BW ≈≈ 25 MHz, modulation speed 25 MHz, modulation speed ≈≈ 0.3 0.3 –– 0.5 b/s/Hz0.5 b/s/Hz•• max capacity/kmmax capacity/km22 ≈≈ 1 Mb/s average, 10 Mb/s peak (packet)1 Mb/s average, 10 Mb/s peak (packet)•• 2 orders of magnitude out2 orders of magnitude out

WLAN (802.11, WLAN (802.11, HiperlanHiperlan))•• cell cell ≈≈ 0.1 0.1 –– 0.5 km, BW 0.5 km, BW ≈≈ 100 MHz, modulation speed 100 MHz, modulation speed ≈≈ 0.2 0.2 –– 0.3 0.3

b/s/Hzb/s/Hz•• max capacity/kmmax capacity/km22 ≈≈ 100 Mb/s average, 1 100 Mb/s average, 1 GbGb/s peak (packet)/s peak (packet)•• capacity ok, but too many access points, limited mobility capacity ok, but too many access points, limited mobility

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Individual Centric Services Individual Centric Services (I(I--Centric)Centric)Emphasis is on the provision of services for Emphasis is on the provision of services for individualsindividuals

ServiceServiceProvidersProviders

FoodFood

TravelTravel

Home ControlHome ControlEE--CommerceCommerce

EducationEducation

HealthHealthCareCare

InformationInformation

Road Traffic Road Traffic InformaticsInformatics

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Wireless Network EvolutionWireless Network Evolution

WPAN radioWPAN radio

Today’s Wireless SystemsToday’s Wireless Systems

LowLow--tier servicestier services

OBEXOBEX IPIP

802.11 Radio802.11 Radio

MACMAC

Mobile ServiceMobile ServiceMiddlewareMiddleware

IPIP

WLAN ServicesWLAN Services

2.5G/3G Radio2.5G/3G Radio

GSM/GSM/GPRSGPRS

2.5G/3G Services2.5G/3G Services

3G Access3G AccessNetworkNetwork

PSTNPSTN IPIP

WPAN networkWPAN networklayer (e.g. Bluetooth)layer (e.g. Bluetooth)

RadioRadio--specific vertically integrated systems withspecific vertically integrated systems withcomplex complex interworkinginterworking gatewaysgateways

Future SystemsFuture Systems

3G/4G3G/4GRadioRadio

WLANWLANradioradio

WPAN/lowWPAN/low--tier radiotier radio

Generic Radio Access NetworkGeneric Radio Access Network

SecuritySecurity QoSQoS VPNVPN ContentContentDeliveryDelivery

Beyond 3G (4G?) ServicesBeyond 3G (4G?) Services

RadioRadio--independent modular system architectureindependent modular system architecturefor heterogeneous networksfor heterogeneous networks

uniformuniformradio API’sradio API’s

genericgenericnetwork APInetwork API

uniform serviceuniform serviceAPI (Internet+)API (Internet+)

Unified IPUnified IP--based mobile networkbased mobile network

supportsupportfor multifor multi--hop,hop,MM--cast, etc.cast, etc.

serviceservicefeaturefeaturemodulesmodules

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Radio Network DevelopmentsRadio Network Developments3G/WLAN Hot3G/WLAN Hot--SpotsSpots•• Use of WLAN in hotUse of WLAN in hot--spots for lower system cost, better endspots for lower system cost, better end--user user

performance and more total capacityperformance and more total capacityInfostationsInfostations•• Use of opportunistic “radio caches” for significant reduction inUse of opportunistic “radio caches” for significant reduction in

average cost per bit, facilitating qualitatively new mobile servaverage cost per bit, facilitating qualitatively new mobile servicesicesSelfSelf--organizing wireless access networksorganizing wireless access networks•• AdAd--hoc wireless network protocols which support multihoc wireless network protocols which support multi--hop and hop and

peerpeer--toto--peer service models, particularly for lowpeer service models, particularly for low--tier uses (intier uses (in--home, sensors, etc.)home, sensors, etc.)

ContentContent--based multicastingbased multicasting•• network service paradigms for “location” and “person” aware network service paradigms for “location” and “person” aware

information delivery to mobilesinformation delivery to mobiles

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InfostationInfostation ConceptConcept

Optimised for high speed access for short periodsOptimised for high speed access for short periodsEnhances service provision over cellular systemsEnhances service provision over cellular systems

Internet/Intranet Internet/Intranet (high speed)(high speed) Low speed wideLow speed wide--area accessarea access

Infostation Infostation Cell Cell (super(super--high speed)high speed)

InfostationInfostation accessaccesspoint (supports cachingpoint (supports caching

and opportunistic delivery)and opportunistic delivery)

Low speed wideLow speed wide--area accessarea access

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Future Service DeliveryFuture Service DeliveryHierarchical, selfHierarchical, self--organizing network concept currently organizing network concept currently under consideration, based on:under consideration, based on:•• 3 service tiers (cellular, WLAN, personal area)3 service tiers (cellular, WLAN, personal area)•• Base Stations (BS), Access Points (AP), Forwarding Base Stations (BS), Access Points (AP), Forwarding

radio Nodes (FN), user devicesradio Nodes (FN), user devices•• automatic discovery and power management protocolsautomatic discovery and power management protocols•• hierarchical, adhierarchical, ad--hoc multihoc multi--hop routinghop routing

Digital Broadcasting (Digital Broadcasting (DxBDxB) has potential for inter) has potential for inter--working with the hierarchical system. working with the hierarchical system.

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DxB DxB Coverage Coverage

AreaAreaDxB DxB

TransmitterTransmitter

3G Cell BS3G Cell BS

3G Cell3G Cell

Hierarchical SystemHierarchical System

WLAN WLAN APAP

WLAN WLAN APAP

low tier sensorslow tier sensorsFNFN

FN = Forwarding NodeFN = Forwarding Node

PANPANFNFN

InternetInternet

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Content Delivery: Content Delivery: User PerspectiveUser Perspective

Content may be delivered by a variety of mechanismsContent may be delivered by a variety of mechanismsUser terminal is likely to evolve into an environment User terminal is likely to evolve into an environment able to accept content from a variety of networksable to accept content from a variety of networksThe user will be able to choose delivery mechanismThe user will be able to choose delivery mechanismThe choice will vary with location, time and service.The choice will vary with location, time and service.This introduces the concept of a Personal Distributed This introduces the concept of a Personal Distributed Environment (PDE)Environment (PDE)This is a key work area for Mobile VCEThis is a key work area for Mobile VCE

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The Personal Distributed The Personal Distributed Environment (PDE)Environment (PDE)

The user The user ““terminalterminal”” is a distributed set of devices which is a distributed set of devices which have a range of capabilities.have a range of capabilities.The user will be able to control access and quality for these The user will be able to control access and quality for these distributed devices whose composition and characteristics distributed devices whose composition and characteristics will be location and time dependent.will be location and time dependent.The user will be empowered to negotiate his/her service The user will be empowered to negotiate his/her service facilities and tariffs at the point of delivery.facilities and tariffs at the point of delivery.The PDE is a key concept in creative interThe PDE is a key concept in creative inter--working of working of wireless and broadcast technologies for enhanced service wireless and broadcast technologies for enhanced service provision.provision.

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PDE StructurePDE Structure

A combination of local devices, connected using PAN A combination of local devices, connected using PAN technologies such as Bluetooth andtechnologies such as Bluetooth and ZigBeeZigBee, and remote , and remote devices using a variety of heterogeneous networking devices using a variety of heterogeneous networking options such as fixed line, cellular and WLAN options such as fixed line, cellular and WLAN technologies. technologies. Devices may join and leave the PDE in a dynamic way Devices may join and leave the PDE in a dynamic way and ( dynamic reconfiguration issues).and ( dynamic reconfiguration issues).In principle the PDE user is able to use any device In principle the PDE user is able to use any device within the PDE to access content stored on any other, within the PDE to access content stored on any other, subject to security constraints, device capabilities, and subject to security constraints, device capabilities, and connectivity issues.connectivity issues.

2020

Intra PDE Device Intra PDE Device ConnectionConnection

PDEPDE

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PDE Device Connection via PDE Device Connection via External NetworksExternal Networks

PDEPDE

2222

PDE IssuesPDE Issues

Personal Access ManagementPersonal Access Management•• Interaction of multiple user devices which may be Interaction of multiple user devices which may be

local and remote to the user and may be dynamically local and remote to the user and may be dynamically changingchanging

Personal Service ManagementPersonal Service Management•• The handling (from the user’s perspective) of multiple The handling (from the user’s perspective) of multiple

services from multiple providers over multiple services from multiple providers over multiple networks.networks.

•• Optimal (service dependent) device configuration.Optimal (service dependent) device configuration.

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Feature Discovery AspectsFeature Discovery AspectsAllows foreign devices and services to determine the Allows foreign devices and services to determine the capabilities of a particular device through interrogation. capabilities of a particular device through interrogation. E.g. a device with a LCD display should be able to provide E.g. a device with a LCD display should be able to provide information on the resolution and colour range of that information on the resolution and colour range of that display upon request.display upon request.Enables opportunistic communication; devices within the Enables opportunistic communication; devices within the PDE with ad hoc networking capabilities would be able to PDE with ad hoc networking capabilities would be able to communicate effectively with other ad hoc networks or communicate effectively with other ad hoc networks or devices encountered. devices encountered. E.g. a BluetoothE.g. a Bluetooth--enabled laptop would be able to make use enabled laptop would be able to make use of a large display that is also Bluetoothof a large display that is also Bluetooth--enabled.enabled.

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Service Discovery AspectsService Discovery Aspects

Service discovery is an analogous procedure aimed at Service discovery is an analogous procedure aimed at identifying the services operating on devices. identifying the services operating on devices. Together service and feature discovery make it possible Together service and feature discovery make it possible for multimedia services to be tailored to suit the end for multimedia services to be tailored to suit the end devicedevice

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Security AspectsSecurity AspectsPDE identity verification (dynamically distributed over a PDE identity verification (dynamically distributed over a number of devices and physical locations) number of devices and physical locations) Authorised accesses to information and services.Authorised accesses to information and services.Information transfers within the PDE must be secure.Information transfers within the PDE must be secure.Parts of the PDE must not be able to act independent of the Parts of the PDE must not be able to act independent of the user in an unauthorised manner.user in an unauthorised manner.Communicating entities and service providers must be able Communicating entities and service providers must be able to trust the PDE, which indicates a Security Information to trust the PDE, which indicates a Security Information Register requirement.Register requirement.Content security, both of user data and data from service Content security, both of user data and data from service providers. providers.

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Device LocationDevice Location

Device location knowledge within a PDE is required so Device location knowledge within a PDE is required so that an incoming service may be directed to a device that an incoming service may be directed to a device capable of accepting that service and which is accessible capable of accepting that service and which is accessible to the user. to the user. Approaches to device location indication include proxyApproaches to device location indication include proxy--based and redirectbased and redirect--based; both of which can be based; both of which can be implemented using The Session Initiation Protocol implemented using The Session Initiation Protocol (SIP), for example.(SIP), for example.

2727

PDE BoundaryPDE Boundary

The PDE is defined as all devices over which the user The PDE is defined as all devices over which the user exerts control (not ownership)exerts control (not ownership)..Control is exercised over logical entities.Control is exercised over logical entities.In a STB the Service Provider controls a section of the In a STB the Service Provider controls a section of the device and can download data at will. device and can download data at will. The user cannot access this section of the device. The user cannot access this section of the device. The user can however control the device by changing The user can however control the device by changing channels, possibly recording to a hard drive, etc. channels, possibly recording to a hard drive, etc. Such a device thus has a logical PDE boundary.Such a device thus has a logical PDE boundary.

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Device Management EntityDevice Management Entity

Device Management Entity (DME)Device Management Entity (DME)

Feature Feature RegisterRegister

Data related to the capabilities Data related to the capabilities of each PDE deviceof each PDE device

Security Security RegisterRegister

Data related to identity and Data related to identity and security policiessecurity policies

Location Location RegisterRegister

Data related to location of each Data related to location of each device (analogous to a SIP device (analogous to a SIP

location service)location service)

Optional Optional EntitiesEntities

Examples: Cache, Examples: Cache, TranscoderTranscoder, , Profile Data, etc.Profile Data, etc.

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BluetoothBluetoothDxBDxBWLANWLANCellularCellular

PDE Sub NetworksPDE Sub NetworksPDEPDEDMEDME

Sub Sub Net 2Net 2

Sub Sub Net 3 Net 3

Sub Sub Net 4Net 4

Core NetworkCore Network

Sub Net 1 = homeSub Net 1 = homeSub Net 2 = carSub Net 2 = carSub Net 3 = officeSub Net 3 = officeSub Net 4 = PAN, etcSub Net 4 = PAN, etc

Network Network Access Access Device Device (NAD)(NAD)

Sub Sub Net 1Net 1

3030

Distributed DMEDistributed DME

The DME may be distributed in natureThe DME may be distributed in nature•• Portion of the DME resides on each subPortion of the DME resides on each sub--networknetwork•• Root (master) DME resides at a Root (master) DME resides at a knownknown locationlocation––Location determined via DNS queryLocation determined via DNS query

PDEPDERoot Root DMEDME

Home Home DMEDME

PAN PAN DMEDME

Car Car DMEDME

3131

Root DME LocationRoot DME Location

Root DME Location OptionsRoot DME Location Options•• 3rd Party Provider3rd Party Provider•• Home NetworkHome Network•• User equipmentUser equipment•• Maintenance of DME may dictate locationMaintenance of DME may dictate location

Root DME Implementation OptionsRoot DME Implementation Options•• Contains cached copies of local DME data entriesContains cached copies of local DME data entries•• Contains only pointers to local DME recordsContains only pointers to local DME records––Redirects enquiries to appropriate local DME Redirects enquiries to appropriate local DME

serverserver

3232

PDE DevelopmentPDE Development

The SIP solution illustrated assumes all devices and The SIP solution illustrated assumes all devices and services are represented in a familiar manner, allowing services are represented in a familiar manner, allowing services to be compared, selected and addressed from a services to be compared, selected and addressed from a SIP database.SIP database.Many PDE devices may be incapable of interacting Many PDE devices may be incapable of interacting directly with a SIP server.directly with a SIP server.Additionally, various discovery protocols, use different Additionally, various discovery protocols, use different data representation formats such as XML and ASN.1, data representation formats such as XML and ASN.1, thereby complicating service selection.thereby complicating service selection.

3333

The Open Services Gateway The Open Services Gateway Initiative (OSGI)Initiative (OSGI)

The Gateway consists of a framework within which The Gateway consists of a framework within which service bundles are added to create functionality as and service bundles are added to create functionality as and when they are needed. when they are needed. This can provide a significant element of the DME at a This can provide a significant element of the DME at a local network level. local network level. A option exists for a SIP server to be implemented as a A option exists for a SIP server to be implemented as a service bundle on the gateway, as shown next, or to be service bundle on the gateway, as shown next, or to be managed remotely. managed remotely. The Gateway can recognise devices and represent them The Gateway can recognise devices and represent them in a common way and in a common way and can register them with a SIP can register them with a SIP server, for example, which can then handle service server, for example, which can then handle service requests.requests.

3434

SIP Server Option in an Open SIP Server Option in an Open Services GatewayServices Gateway

Wide AreaWide AreaNetworkNetwork

Service ManagementService Management

GATEWAYGATEWAY

LocalLocalNetworkNetwork

OSGI FrameworkOSGI Framework

Serv

ice

ASe

rvic

e A

Serv

ice

BSe

rvic

e B

SIP

Serv

erSI

P Se

rver

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ConclusionsConclusions

3G multimedia will happen even though late 3G multimedia will happen even though late –– valuable valuable learning for new serviceslearning for new services4G visions herald new generation of thinking about 4G visions herald new generation of thinking about design of mobile/wireless systems (it is not just a new design of mobile/wireless systems (it is not just a new standard)standard)In 4G a mobile terminal is not just for communications In 4G a mobile terminal is not just for communications –– it will manage all aspects of lifeit will manage all aspects of lifeBusiness models will change to incorporate service Business models will change to incorporate service negotiationnegotiationResearch for 4G systems will influence evolution via Research for 4G systems will influence evolution via 3G/3G+3G/3G+