Transcript Document

Mobile Phones
(The next generation)
Justin Champion
Ext 3273
[email protected]
Slides available at
www.soc.staffs.ac.uk/flk1
2.5G +
Contents
Problem with Mobile computing
Why 2.5G
Mobile Computing
 Biggest problem with Mobile communications like the
Internet is too many acronyms
WSP/B PDC POS CCIR BW UPT BSS MCC FHSS HIPERLAN IFS FIB SNDCP S-SAP WWW MSISD N LAI PDA ATIM CW DVB-T
ICMP PSN TTL HEC GIF LAPD CSCW ISO ITU LED CCH CDMA PA ITU-R PDN IEEE IrDA AIDCS CAC HTML CC NDC CCA
SNACK IMF JPEG HDTP DPCH HDB HO GWL CC XOR TD-CDMA JDC ISI RTT CTS BCA GTP SIM MMF CEPT SCPAS-TP SFD
UBR DPCCH SDM PTP-CLNS RL URI PHS TLLI MOT CU UIM PPP AIB MNC WRC IMT-MC WSP WAP ATM-CL LBR PMA TCH/F
M-PNNI HCSAP EMAS EIRP CATV DNS V+D FW CSMA DSL FSK PLL AESA CSMA/CD VC DH HDLC TI RAS MN SDP DVTR
CORBA GEO EDTV HMQoS TCH/FS HEO PAD HO-HMPDU SAP SDMA WML EHF HIB FEC FIC TC-HMPDU VDB AID ACT FR
PRACH AFS CIF LI PACS RIP Loc AGCH ASA IWF BLIR TR-SAP UDP SCF IMT-FT Cnf ISDN HTTP BPSK TFO ESS RTT TMN
MSRN SN PDO GMSC SIG CN HDTV AUS TUSSD CT SMS DFWMAC DHCP BSC KID ROM ETSI ISM QPSK UTRA GRE TM Req
DVB-S FPLMTS CCCH ISL MUL DC COFDMOSI AM DVB RTR SEQN COMS RSS PS PM TOS PC DAB PCS LS RSA RRM CN TE
IS XML LF SS7 M-NNI HI T-SAP COA VCC PTP CS PTM WMLScript MTSA BLIRCS RR IMSI DAMA RAND MIB GMM PCH RA
NSS LIR SH SDT BSSAP SAAL MATM WTLS TIM FT JCT PDTCH GFSK D-AMPS CDM PCM CSD SW UMTS IV PSK STA RIB
EMAS-E MSDU TA RFC CLMS IR NMT RLP ACID TINA DQPSK TFI GPRS PACS-UB VHF PT ABR NSA WCAC NTSC EY- PMA
TMSI TDT WDP CPU HMPDU SDU PLW DVB-C HAD CSMA/CA ACL MOC MACA Disassoc TDM LAN DPDCH PLMN DLC QAM
EIR AuC HID RM DA PLCP CM SNAP LOS CAC VNDC UHF WCMP L2CAP ARIB MSK ECDH TETRA PHY DSDV HA TCH/H ASCII
SRES WTA GSN CRC W3C PAL BRAN PSTN MEO MCM CKSN CVSD I-TCP SUMR HSCSD LC RT POTS HDACS TTC ASK
FDMA T-TCP VBR-rt LRU BER DIFS BSS PPG HDML EDGE PRMA MSC NA-TDMA BFSK SDTV TCP GMSK MS VPN NAT AMA
SCO IMT-DS HF HCPDU USIM TCH/HS DS GPS CGI PLI WIM SDCCH NMAS MCI IMT-TCCPM OFDM TIB ANSI BCCH ASP NFS
ITU-T SFN TFTS WMT MHEG ATM NIB RLC WAN SGSN DECT PMD WTAI FCCH FM CAMEL FA COS QoS UE PI TDD SCDMA
LMP ARQN DCS VLR SATM VBR-nrt HM ACK SwMI FACCH DCCH LAPDm AK-HCPDU DT-HCPDU WLAN SHF VAD SIFS WLL
RA MSC PSF W-CTRL GP FDD UWC BSSGP BCH MT ID SMRIB UTRAN NNI PIFS GGSN HCSDU IMT OMC AAL WTP DCF SCH
FCA PDU IN IMT-SC SA PSPDN GERAN GSM EDGE RAN M-UNI DSR TCH MAC RNS BMP OSS W-CDMA SCPS AMES IP
WATM SC Auth SEC-SAP MF MS CBR NRL DSMA DBPSK 3GPP HC TDMA ML MTC NAV AP M-TCP MBS PTP- ONS SC UD TSF
PDF GSM ADSL UNI LEO MSAP PIN FDM PCF SSL BTSM ISMA VLF OTA ADA SACCH DSSS RACH PUK PPM SAMA MM LAPC
IOT PAD RTS Res ICO DTIM HBR CD TLS VBR DVD MSIN HCQoS LA DDIB SS PNNI CIDR DTMF MSC EIT IMEI Codec UP ARQ
UN ILR WAE IETF CDV Assoc HP DCA MH CDPD GAP LLC BTS LM B-ISDN HLR M-QoS TPC TV WPAN SI RAL GR WP-CDMA
AMPS NIT BLI MPEG VHE PCS CCF
2.5G +
Where are phones going
Developing from traditional devices for voice
calls
3G UMTS
Voice calls are close
Increased data use
SMS
MMS
Video on Demand
Location based services
2.5 G
EDGE
GPRS
2G
GSM
2.5G +
Why use 2.5G phones at all
The network was not designed to handle data
calls
Infrastructure had to be put in place to allow data to
move across the network
Handsets were not ready to be used with data
intensive applications
• Battery life was a consideration
• Processor capability
• Services to provide for the new data capacities
Money for infrastructure
• The amount of money invested in the licenses left very little
for the required upgrades/new base stations
2.5G +
 3G spectrum auction
License shows the size of the spectrum with A being the
largest
 Part of the auction rules was a new company in the UK won
the License type ‘A’
 Auction closed on the 27th April 2000
License
A
B
C
D
E
Company
TIW (3)
Vodafone
MM02
One2One (T-Mobile)
Orange
Paid (Pounds)
4,384,700,000
5,964,000,000
4,030,100,000
4,003,600,000
4,095,000,000
General Packet Radio Service
 2.5G Data Use Today
General Packet Radio Service (GPRS)
 Introduced to allow an increased data rate over
an existing GSM infrastructure!
 Requires some additional servers and
upgrades to BS
 Standard released by European
Telecommunication Standards Institute (ETSI)
in March 1998
 To use this you need a GPRS enabled device
• GPRS devices are backwards compatible with
GSM
General Packet Radio Service
 General Packet Radio Service (GPRS)
 Features
 Higher data connections speeds
• Theoretical Maximum of 171 Kbps
• Does not consider though
 Interference
 Distance from transmitter
 All GSM channels would have to be dedicated to GPRS
communications
 Any error-correction
 Device uploading data
• Actually speeds with conditions taken into account is theoretically a
maximum of 53.6 Kbps
 Studies have shown the average is usually about 20 – 40 Kbps
 Always on Data communications
• No delay in setting up a data communication
General Packet Radio Service
 GPRS Devices
In the standard there are three types of GPRS devices
A
• Capable of Simultaneous data transfer and voice communications
B
• Automatic switching between voice and data calls. This will need to
be configured on the device itself
C
• Switching between data and voice operated by the device user
manually.
All of these standards are backwards compatible with the
GSM networks for voice communications
General Packet Radio Service
 GPRS
Relies on the fact that Internet communications are bursty
in nature
 A large amount of data will be received and the user will
process it before requesting more i.e. a web page
 A single voice circuit will from GSM will be broken into smaller
parts and the GPRS data is sent on this circuit.
All data is sent in packets
 Data must be broken into small packets
 These packets are re-assembled at the destination
 These packets add an overhead in the form of the packet
header
General Packet Radio Service
 GPRS Channel Breakdown
Channel
Use of the Channel
0
Voice
1
AAAABBABBAAAAFA
2
Voice
3
Voice
4
Voice
5
BBBBABABAFFFFFFF
6
Voice
7
FFAFFAFFABABBBBB
Data Users
A = User 1
B = User 2
F = User 3
In this instance we
have 5 voice calls and
3 users receiving data
General Packet Radio Service
 GPRS Channel Breakdown Continued
A channel which is being used for GPRS data
 Can only be shared between other GPRS users
 It can not be allocated in that time slot for GSM voice calls
• Even if part of the time slot is available
 The use of GPRS will reduce the amount of voice calls that
can be made on that cell
 With enough data calls a cell will become useless for voice
callers, which require exclusive access to the time slots
General Packet Radio Service
 GPRS Infrastructure
As discussed earlier GPRS build upon the GSM networks.
Network elements need changing
 Base stations
• Requires a software upgrade
 Base station controller
• Requires a software upgrade
New parts need adding
 Serving GPRS Support Node (SGSN)
• Has VLR functionality
 Authorise attached users
• Details recorded of data packets to be charged for
• Session Management
• Router for packets which may be lost during a handover during a data
call
General Packet Radio Service
 GPRS Infrastructure continued
 Gateway GPRS Support Node (GGSN)
 Is the connection into the GPRS network
 It carries out all translations that area required
 Firewall for the network
 Collates data regarding the amount of packets received
• Potentially in the future this will allow for competing GGSN’s in a network! Free
market choosing either the cheapest or most reliable GGSN!
 There are 3 types of GGSN
• A – Near Future/Now
 The GGSN becomes part of its own ISP and provides Internet services. The
devices will be assigned IP address using DHCP.
• B – Now
 The SSGN always selects the same GGSN to do the Internet work. The
configuration will be done dynamically and on a temporary basis
• C – Future
 This allows a private company to have its own GGSN, with an encryption
key so that only authorised devices can gain access. i.e. a VPN into a
network, constant email access etc
General Packet Radio Service
General Packet Radio Service
 Packet Control Unit (PCU)
Logically separate but usually part of the Base station
controller
 Responsible for the radio interface of GPRS
 Deals and routes packet based communications
 GPRS and SMS
SMS messages are sent in GPRS as a part of the normal
data channels
 In GSM they are usually sent via the control channels
Why
 This changes has taken place ready for the Multimedia
Messaging service
• Due to the size of the messages
2.5G +
Data use
GPRS does allow data use in the network
Does not have a high throughput
Suffers with a high latency in communications
• (www.sourceo2.com/O2_Developers/O2_technologies/GPRS/Technical
_overview/gprs_latency_factors_diagram.htm, 2004)
• Average 0.6 Seconds for a ping packet
This can be an issue with video-on-demand, online
Games
• Poor quality packet error checking
2.5G +
 Enhanced Data GSM Environment
 Developed by Erricson for the benefit of the losers in the 3G spectrum
auctions
 EDGE operates at a theoretical 384Kbps
 This means a company which lost in the auctions can still offer a
reasonable data service
 Companies which invested in the 3G licenses will also benefit as the
infrastructure put in for GPRS and EDGE will still be used with UMTS (3G)
 Current infrastructure
 The current Base stations will require a new transceiver and a software
upgrade to allow EDGE transmission
• This can take place as and when the normal BS are being serviced
 This allows for a wider coverage than will be available at least initially with
the UMTS network.
 Obviously there are still the same issues as GPRS in respect that a
channel that is used for EDGE takes one away from a voice call
2.5G +
 How does EDGE increase the data rate?
New Modulation technique
 8-PSK is used to modulate data
 Allows the encoding of 3 bits in each modulation
• This is the main reason why it is 3X faster than GPRS
• Allow more bits encoded it is also more sensitive to errors
• The receiver / transmitter need to be close together
2.5G +
 How does EDGE increase the data rate?
Improved Error handling
 Packets can be resegmented
 Quality of signal calculation is carried out continuously
• This allows a better prediction of the number of error in the
radio environment at any time
• Giving an improved estimate at the best modulation technique
to use
 If the quality of the signal is not good enough for EDGE
the device will change to the highest GPRS speed
2.5G +
 EDGE Quality
 The code rate indicates how much of the packet is data
(including headers) and how much is error checking code
 MCS3 indicates that 15% of the packet is error checking code
Modulation
Data Rate
Modulation Technique
Code Rate
MSC1
8.8 Kbps
GMSK
0.53
MSC2
11.2 Kbps
GMSK
0.66
MSC3
14.8 Kbps
GMSK
0.85
MSC4
17.6 Kbps
GMSK
1
MSC5
22.4 Kbps
8PSK
0.37
MSC6
29.6 Kbps
8PSK
0.49
MSC7
44.8 Kbps
8PSK
0.76
MSC8
54.4 Kbps
8PSK
0.92
MSC9
59.2 Kbps
8PSK
1
2.5G +
 EDGE will be used this year
 Vodafone have announced they will turn on the transmitters
 Initially for business users in Manchester, London and Liverpool
 (www.computerweekly.com/Article127287.htm, 2004)
 Edge Rollout Stages
 Phase 1 (we are here)
 Introduce single and multi-slot packet switched services
 Introduce single and Multi-slot circuit switched services
 Phase 2
 Web Use
 Email
 Real-time services
• VOIP
• Video Conferencing
2.5G +
 EDGE changes to infrastructure from GPRS
New software required on BS and BSC
 Base station System GRPS Protocol (BSSGP)
• Software to deal with
 Different quality of services are required require minor
changes to the GPRS standards
 Packet types which will be transferred
 New transceiver required on the BS to decode the newly
modulated signals
3G
 Third Generation (3G) devices
In Europe this is Universal Mobile Telecommunication
Standard (UMTS)
 Developed by ETSI
 Frequencies are
• Uplink 1920 – 1980 MHz
• Downlink 2110 – 2170 MHz
• commonly referred to as the 2.2 GHz range
 UMTS is based on the IMT-2000 standard for 3G developed by
International Telecommunication Union (ITU)
• The intention was for everyone to use the same technology an
frequency worldwide
• The other widely used standard is CDMA2000 used in America
• UMTS is used in Europe and Japan
3G UMTS
 Intention
Allow data communications at up to 2Mbps
Packet driven rather than circuit
 For voice and for data transmissions.
 Packet based networks allow for an increased amount of traffic
on a medium.
 The only time part of that medium is blocked is when a device is
transmitting or receiving.
• Consider how often in your phone calls you actually say nothing
 Natural pause between words
 Taking a breath
 Waiting for a response
 Thinking of something to say!
3G UMTS
 UMTS
Offers voice and data services
 Services offered will be classed into one of the following
Conversational
Streaming
Interactive
Background
Real-Time
Voice
Streaming
Video
Best-effort, guarantee of quality
delivery
Web Pages
MMS, SMS,
emails
 From these classes certain defined Quality of Service (QOS)
specifications are guaranteed like packet delay time
3G UMTS
 Intended Data Rates
Low
 144 kbits/s
• satellite and rural outdoor
Medium
 384 kbits/s
• urban outdoor
High
 2048 kbits/s
• indoor and low range outdoor
The speed that the device is moving at will effect the data rate
 Maximum movement speed for high date rate is 10 Kmph a fast
walker will lose this rate
3G UMTS
 Types of Cells and Base station to use them
Macro Cell
 These cover a large area and will give slow access
 144 Kbps – max speed of 500 Km/h
Micro Cell
 These should cover 100 – 250 metres
 384 Kbps max speed 120 Km/h
Pico Cell
 Less than 50 metres
 2 Mbps – max speed of 10 Km/h
 Difficult to predict
Actual distances and bandwidth depend on local conditions
3G UMTS
 Types of Cells and Base station to use them
Cells will operate in a hierarchy overlaying each other
Global
Satellite
Suburban
Urban
In-Building
Micro-Cell
Macro-Cell
Pico-Cell
2.5G +
 What throughput to actually expect
For EDGE and UMTS as they are not operational it is
difficult to be accurate
 Figures taken from
(www.esdaniel.net/_Rainbow/Documents/CIO_%20Wireless_
%202003.pdf, 2003)
Technology
Throughput Kbps
GPRS
20-40
EDGE
80-100
UMTS
200-300
3G UMTS
 What to do with this technology
 Even with the data rates being lower in reality from theory there
needs to some application to make use it
 At the moment no Killer Application is available
• MMS has not been the success that was intended
 Main problem with MMS is a lack of the devices and the cost
 Europe Test Bed for 3G
 Was the Isle of Man
• MM02 were given a FREE license to experiment
 Services started in May 2001
• The idea being to test the system and to find a potential Killer application
 (www.mobilecomms-technology.com/projects/manx/, 2003)
• Result was nothing conclusive was found
 Japan
• Who have been using UMTS 3G since 2002!
• Have found that the Killer application is E-Mail
 3G data Rates are not required for this !!
2.5G +
Useful links
Official site for the UK 3G frequency auction
www.ofcom.org.uk/static/archive/spectrumauctions/a
uction/auction_index.htm
Discussion of a 3G killer application
(www.wmrc.com/businessbriefing/pdf/wireless_2003/
Technology/highdeal.pdf, 2003)
Details of what was paid in Europe for 3G
spectrum licenses
(http://www.cellular-news.com/3G/, 2002
2.5G +
Summary