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UMTS

UMTS. Justin Champion. 3G UMTS. Contents Why 3G UMTS Smart Antenna Use of UMTS at the moment. 3G UMTS. The Dream (intention) 2G and 2.5G systems are incompatible around the world.

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UMTS

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  1. UMTS Justin Champion

  2. 3G UMTS • Contents • Why 3G • UMTS • Smart Antenna • Use of UMTS at the moment

  3. 3G UMTS • The Dream (intention) • 2G and 2.5G systems are incompatible around the world. • Worldwide devices need to have multiple technologies inside of them, i.e. tri-band phones, dual-mode phones • To develop a single standard that would be accepted around the world • One device should be able to work anywhere ! “Access to Information from Anyplace, Anytime”

  4. 3G UMTS • The Dream (continued) • Worldwide positioning available • Able to pinpoint a device and direct services to it. • Mostly to be used for “Push” services • Increased data rate • Maximum 2048Kbps • Operational • in Europe by 2002 • Japan 2001 (this was achieved) • Worldwide usage by 2005 (not going to happen)

  5. 3G UMTS • The reality • Different standards with some operators in America and the rest of the world • In the future market forces may move towards a single standard • i.e. VHS and Betamax video tapes • Difficulties • World wide identical available spectrum • Agreement on the encoding/decoding technique used • Local influence groups • Manufacturers who have invested in one technology

  6. 3G UMTS • Universal Mobile Telecommunications System (UMTS) • Generic name for 3G developments • Being developed by the European Telecommunications Standards Institute (ETSI) • Based on the specifications of IMT-2000 developed by the International Telecommunications Union (ITU) • Frequency Spectrum • Technical Specification • Radio and Network components • Tariffs and Billing • Technical Assistance

  7. 3G UMTS • Standard • The 3G stand was written by the International Telecommunication Union (ITU) • The standard was referred to as IMT-2000 • The key to the standards was the available data over the air interface • 2Mbps in fixed or in-building environments • 384 kbps in pedestrian or urban environments • 144 kbps in wide area mobile environments • Variable data rates in large geographic area systems (satellite)

  8. 3G UMTS • Other parts of the standard • Frequency Spectrum • Technical Specification • Radio and Network components • Tariffs and Billing • Technical Assistance • 3 Main technical implementations were agreed • UMTS - Europe • CDMA2000 - America • TD-SCDMA –China

  9. 3G UMTS • Universal Mobile Telecommunication system (UMTS) • UMTS • Builds upon the successful European GSM network • Incorporates the developments made for the GPRS and EDGE networks • Five areas of standardisation • Radio • Core Network • Terminals • Services

  10. 3G UMTS • The core network • Asynchronous Transfer Method (ATM) • Has been defined as the core networking technology • ATM allows circuit switched transfer of data using packets. • High speed data transfer – currently maximum 10 Gbps • Guarantee of quality of service for the duration of packet transfer • Small packets used called cells for the transfer of data to minimise the impact on the routers, network and switches. • IPv6 • Arguments are being pushed for the core network to allow IPv6 • RFC3314, September 2002 • This would allow packets to be transferred directly from the internet to the device with no translation • IPv6 does contain QOS headers, which can be used with the correctly configured hardware • All 3G devices could have a single IP address that would not need to change

  11. 3G UMTS • UMTS • Full packet driven architecture • 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

  12. 3G UMTS • UMTS • Offers voice and data services the same as EDGE • Services offered will be classed into one of the following • From these classes certain defined Quality of Service (QOS) specifications are guaranteed like packet delay time

  13. 3G UMTS • Intended Data Rates • Actual data rates will be effected by • Interference (other devices, background, buildings) • Over use of the frequency • Amount of other traffic • Base station / cell actually attached to • Speed you are moving at !

  14. 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 a medium area • 384 Kbps max speed 120 Km/h • Pico Cell • Less than 100 metres • 2 Mbps – max speed of 10 Km/h • Difficult to predict • Actual distances and bandwidth depend on local conditions

  15. 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

  16. Global Satellite Suburban Urban In-Building Pico-Cell Micro-Cell Macro-Cell 3G UMTS • Types of Cells and Base station to use them • Cells will operate in a hierarchy overlaying each other

  17. 3G UMTS • Types of Cells and Base station to use them • Cells will operate in a hierarchy overlaying each other • Pico Cells will operate in a Time division Duplex (TDD) mode • TDD mode will use the same frequency to send and receive with a time frame being allocated. • All other cells will operate in Frequency Division Duplex (FDD) Mode • FDD will operate in the same manner as GSM, with a different frequencies for the Uplink and Downlink

  18. 3G UMTS • Consider • These data rates are in Mega Bits per Second and Kilo Bits • In terms of data rate the measure of a kilo bit is 1000 bits • Not the 1024 which is used for data storage • So • 2 Mega Bits per Second = 244 Kilo Bytes per second (roughly)

  19. 3G UMTS • What transmitters/base stations look like • Pictures taken from (www.undetectables.co.uk, 2004)

  20. 3G UMTS • Radio Interface • Allocated Frequencies

  21. 3G UMTS • Radio Interface • These frequencies were auctioned at great expense • The UK phone companies in June, 2003 said that they would claim the VAT back on the license purchases! About £4 Billion pounds • Court case started on the 9th of Feb 2004

  22. 3G • 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 • The UK phone companies in June, 2003 said that they would claim the VAT back on the license purchases! About £4 Billion pounds • Court case started on the 9th of Feb 2004

  23. 3G UMTS • UK 3G Winners ??

  24. 3G UMTS • Radio Interface • UMTS uses Wideband-Code Division Multiple Access (W-CDMA) • Also known as “IMT-2000 Direct Spread” • Extremely complex algorithms • Uses 10x the current 2G processing power! • Modulation is done with Quadrature phase shift keying (QPSK) • This encodes 2 bits with each change • Supports two modes of operation • Frequency Division Duplex (FDD) • Time Division Duplex (TDD)

  25. 3G UMTS • Trivia • Spread spectrum technology was patented by Actress Hedy Lamarr in 1942 • She was the person who also gave us Cat woman out of the Batman comics!

  26. 3G UMTS • W-CDMA • Operates in the same manner as the CDMA used in the US • CDMA allows multiple users to communicate at the same time over the same frequency • Each of the devices is given a “Chipping code” this is known by the device and the base station. • This chipping code is then used to identify the signal and allows the BS to receive the signal • The chipping code is used to adjust the frequency of data transferred during the transfer • The essential point of CDMA is the use of power control

  27. 3G UMTS • W-CDMA • Wideband CDMA operates the same but this takes place over a wider area of frequency • UMTS uses 5MHz for the signal • CDMA (narrowband) uses 200 KHz • These communications are secure by the nature that unless the chipping code is known, the sequence of the data can not be known • Communications can take place as soon as the device is ready and frequency reuse factor is now one

  28. 3G UMTS • W-CDMA • Frequency Reuse Factor • This is the distance which needs to be left between cells • As the same frequency is reused and the chipping code which is used is change and unique to a BS • The frequency can be reused in adjoining cells • Temporary Base stations can be added to the infrastructure if required, as long as the chipping code was unique

  29. 3G UMTS • Power Control • If you consider a group of people speaking, Chinese, English and Italian • If these all speak at the same volume you can then listen for the parts which you understand. • If the English person starts talking louder than the rest, the all you will hear is English • The other languages will be drowned out • CDMA Works on the same basis • One point of CDMA is the power control, so that the power sent out is just enough to allow data transfer to take place. • As a side effect of this technology this controlling of the power that the radio interface uses, also saves the battery on the device

  30. 3G UMTS • Radio Interface • Smart Antenna technology • These will allow the maximum radio efficiency • Traditional Antenna’s are omni-directional • They transfer the radio signal in 3600 from the transmission point Top View Side View

  31. 3G UMTS • Radio Interface • Smart Antenna • Increase the quality of the signals • Only installed at the BS, not the handset • Increase the usage of the BS • Increased frequency reuse

  32. 3G UMTS • Radio Interface • Smart Antenna • Two types at the moment • Switched Beam • A finite number of patterns or technologies are built into these • Adaptive Array • Infinite Number of patterns available, these patterns will adjust in real-time to conditions

  33. 3G UMTS Adaptive Array Antenna Switched Beam (http://www.iec.org/online/tutorials/smart_ant/topic03.html, 2003)

  34. 3G UMTS • Smart Antenna Benefits • (www.iec.org/online/tutorials/smart_ant/topic04.html, 2003)

  35. 3G UMTS • Radio Interface • Smart Antenna • Switched Beam • Multiple direction orientated fixed beams • Multiple beams can be combined to improve the quality of the signal • Each of the beams is referred to as a Macro sector • The macro sector with the strongest signal in the centre of the antenna will be the one which communications will be directed through • As the user moves the Macro sector to the new highest power • Done by monitoring the strength of the signal Darker colour shows more sensitive part of antenna

  36. 3G UMTS • Radio Interface • Adaptive Array Antennas • These devices track a communicating device • The power can be adjusted to exactly what is required for successful communications • They can minimise interference by controlling the power in a particular direction • The transmission of the signal can be directed to the user and follow them. • This removes any interference from other users • Reduces the effect of signal propagation • As the signal is directed

  37. 3G UMTS • Advantages • Integration • Switched beam can be added to current infrastructure • Adaptive antenna, require consideration to the network and there use • Range • Switched beam can increase range between 20 – 200% over a normal cell • Depending on local conditions • Switched beam power can not be adapted as the user moves, as the power and shape are pre-defined • Adaptive Array can cover larger area due to the directing of the signals to a device • Interference Suppression • Switched beam Interference from beams which are away from where they are expected are ignored • As the beams are pre-determined at the development stage, interference is still possible • Switched Beam has problems with interference from device which are close to the BS • Adaptive array is more resistant to interference as the signal is narrowed towards the actual device • Capacity • See next slide

  38. 3G UMTS • Smart Antenna Capacity • Spatial Division Multiple Access (SDMA) • More efficient use of the allocated frequency • By controlling • Amount of interference • Multi-path Propagation • Multi-path interference • Allowing 2 users in the same cell to use the same transmission slot • Potentially having a single user per allocation slot • This is more of a consideration with WCDMA rather than GSM tech

  39. 3G UMTS • Smart Antenna • Where can this technology be used? • Although it is now being discussed for 3G • It can be use anywhere • GSM, GPRS, EDGE, PDC • UMTS, CDMA2000 • WI-FI, HIPERLAN • The technology is now coming available and this respect it is considered more for 3G

  40. 3G UMTS • W-CDMA • Infrastructure

  41. 3G UMTS • W-CDMA – UTRAN • The core network for 3G will remain the same as GSM • This is a purely cost issue, in the future the infrastructure will be upgraded

  42. 3G UMTS • W-CDMA • UMTS Terrestrial Radio Access Network (UTRAN) • A device which wishes to communicate need’s to request access to the network • This is to prevent too many devices communicating at once • Although CDMA will theoretically allow a very large number of user to communicate at once • What actually happens is the quality of the calls is reduced considerably • This is a issue for voice but is a disaster for data calls

  43. Node-B Node-B Node-B Node-B Node-B Node-B 3G UMTS • W-CDMA • Handover • UMTS will use a soft handover technique • GSM used a hard handover technique • In a handover the device is always attached to at least one BS

  44. – 3G UMTS • Virtual Home • As a part of the ITU standard the Virtual Home Environment (VHE) will be supported. • In 2G a VLR was used to allow the transfer of personal information • A VHE will take this one stage further • This will provide a common look and feel interface • This is independent of the location, connecting network and device • It is envisaged that this will be used on both circuit switched and packet switched networks • How this will be achieved is undecided at the moment

  45. – 3G UMTS • 3G UMTS is working in one part of the UK • Isle of man has the equipment to use 3G • This equipment is run and operated by O2 • The license spectrum used on this island was given free by the government • The actual devices used were given to some of the islanders • The idea was to trial the equipment in a limited manner • Also they wanted to see if there was a pattern of usage for the technology i.e. the killer app • As it is known now they have not found the single killer app, like SMS was for GSM • Japan • When we consider Japan for the killer app it was email! • 3G bandwidth is not needed for email!

  46. 3G UMTS • UMTS Worldwide usage

  47. UMTS • Links • Details of the 3G license auction (UK) • www.umts-forum.org/servlet/dycon/ztumts/umts/Live/en/umts/Resources_Licensing_UK • UMTS standards documents • www.3gpp2.org/Public_html/specs/index.cfm

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