Advanced Mobile Phone System

8/6/2019 Advanced Mobile Phone System

1/7


2/7

Existing 800 MHz D-AMPS operators can use the 1900 MHz spectrum to increase capacity and develop

new user segments in their 800 MHz networks. For example, 800 MHz cells can provide wide-area

coverage (through macro-cells) and act as umbrellas for 1900 MHz micro- and picocells. The small cellscan cover the indoor office environment, shopping malls, airports and hot spot coverage. The umbrella

cells would carry the signals for fast-moving subscribers and fill in gaps in between two isolated

microcells.

D-AMPS 1900 mobile phones will be marketed initially in single-band 1900 MHz as well as dual-band800/1900 MHz versions. In the long run, dual-band versions may prove themselves able to replace single-

band versions at both 800 and 1900 MHz.

AMPS Network Layout

The D-AMPS 800/1900 system architecture is similar to most other cellular system architectures (e.g.GSM network architecture). It contains a Switching System, an Operation and Support System, base

stations and mobile station.

The switching system

The Switching System contains five main functional entities:

The Mobile Switching Center (MSC) performs the telephony switching functions for the network.It controls calls to and from other telephone and data communications networks such as Public

Switched Telephone Networks (PSTN), Integrated Services Digital Networks (ISDN), Public Land

Mobile Networks (PLMN) and Public Data Networks.

The Visitor Location Register (VLR) database contains all temporary subscriber informationneeded by the MSC to serve visiting subscribers who are temporarily in the area of the MSC.

The Home Location Register (HLR) database stores and manages user subscriptions. It contains all

permanent subscriber information including the their service profile, location information andactivity status.

The Authentication Center (AC) supports authentication and encryption functionality. It verifies

the users identity (by authitication) and ensures the confidentiality of each call (by encryption) .This protects network operators against fraud.

The Message Center (MC) supports messaging services.

The base station
http://www.wirelesscommunication.nl/reference/chaptr01/telephon/gsm/gsmnetw.htmhttp://www.wirelesscommunication.nl/reference/chaptr01/telephon/gsm/gsmnetw.htm


3/7

The Base Station is the radio equipment needed to serve each cell in the network. One base station site

may serve more than one cell.

The Operation and Support System

The Operation and Support System supports operation and maintenance activities in the network to allowfor reliable and cost-efficient operation.

The mobile station

IS-54 and IS-136 (Digital AMPS)

IS-54 is the standard for the digital version of the US AMPS system. Recently IS-54 has been replaced bythe IS-136 standard. The system uses and hybrid Frequency Division Multiple Access and Time Division

Multiple Accessconcept as it accepts 3 users per carrier. The carrier spacing 30 kHz, similar to the analog

AMPS. Thus, assuming that the analog and digital system use the same frequency reuse pattern, the digitalversion can accommodate three times more users. In terms frequency planning the digital system behaves

similar to analog AMPS. Carrier frequencies are in the 800 and 1900 MHz bands.

Although the digital system has advantages for the operator, marketers found it difficult to convince

subscribers to go digital, i.e., to buy a new phone. The advantages of improved security in a digital systemwere intentionally not used, to avoid that subscribers would be alerted that the analog AMPS system had

less security.

Radio Aspects

Channel bit rate 48.6 kbit/s

Frame duration 40 ms, divided into six 6.67 ms slots. If follows that for usual carrier frequencies,

on the average one fade per bursts occur. See Spreadsheetv = 27 m/s, fc = 1900 MHz, fade margin6 .. 10 dB)

Each slot: 324 bits, 260 user data

Full rate and half rate codebook excited linear predictive coding:

Vector Sum Excited Linear Prediction (VSELP)

Source rate 7.95 kbit/s, transmitted at 13 kbit/s Differential QPSK (not constant envelope: power penalty) pi/2 shifted, root cosine roll-off

filtering, roll-off factor 0.35

1.62 bit/s/Hz

Idle voice channels can be used forCDPD packet data transmission.

Equalization was initially not included in the standard, but appears useful for delay spreads larger

than T/8, with Tthe symbol time. This corresponds to delay spreads of a few microseconds.

EXTENDED AMPS

Proposed by Hughes

Digital Speech Interpolation (DSI): Speech pauses are exploited to enhance user capacity.

Typically speech activity is about 0.4. Compare withPRMA.
http://www.wirelesscommunication.nl/reference/chaptr01/telephon/amps.htmhttp://www.wirelesscommunication.nl/reference/chaptr04/multi/fdma.htmhttp://www.wirelesscommunication.nl/reference/chaptr04/multi/tdma.htmhttp://www.wirelesscommunication.nl/reference/chaptr04/multi/tdma.htmhttp://www.wirelesscommunication.nl/reference/chaptr04/multi/tdma.htmhttp://www.wirelesscommunication.nl/reference/chaptr05/digimod/digital.htmhttp://www.wirelesscommunication.nl/reference/scripts/ray_time.htmhttp://www.wirelesscommunication.nl/reference/chaptr01/dtmmsyst/cdpd/cdpd.htmhttp://www.wirelesscommunication.nl/reference/chaptr01/dtmmsyst/cdpd/cdpd.htmhttp://www.wirelesscommunication.nl/reference/chaptr04/multi/prma.htmhttp://www.wirelesscommunication.nl/reference/chaptr04/multi/prma.htmhttp://www.wirelesscommunication.nl/reference/chaptr01/telephon/amps.htmhttp://www.wirelesscommunication.nl/reference/chaptr04/multi/fdma.htmhttp://www.wirelesscommunication.nl/reference/chaptr04/multi/tdma.htmhttp://www.wirelesscommunication.nl/reference/chaptr04/multi/tdma.htmhttp://www.wirelesscommunication.nl/reference/chaptr05/digimod/digital.htmhttp://www.wirelesscommunication.nl/reference/scripts/ray_time.htmhttp://www.wirelesscommunication.nl/reference/chaptr01/dtmmsyst/cdpd/cdpd.htmhttp://www.wirelesscommunication.nl/reference/chaptr04/multi/prma.htm


4/7

Frame of six slots; dynamically assigned to different users Example of DSI performance:

o No DSI: E-AMPS has 6 times capacity of analogue AMPS

o DSI on 1 RF carrier: 6 times analogue

o 3 RF carriers: 7 times analogue

o 8 RF carriers: 9 times analogue

o 19 RF carriers: 11 time analogue

o Many RF carriers: Law of large numbers:

o ultimately 6 / 0.4 = 15 times analogue AMPS DSI in forward link: multiplexing

DSI in reverse link: random access: throughput loss because ofcollisions

Slow frequency hopping: mitigates effect of fading

Generations of Mobile Wireless Technologies

Mobile wireless industry has started its technology creation, revelution and evolution since early 1970s. In

the past few decades, mobile wireless technologies have experience 4 or 5 generations of technology

revolution and evelution, namely from 0G to 4G. The cellular concept was intoduced in the 1G technology

which made the large scale mobile wireless communicaton possible. Digital communication has replacedthe analogy technology in the 2G which significantly improved the wireless communication quality. Data

communication, in addition to the voice communication, has been the main focus in the 3G technologies

and a converged network for both voice and data communication is emerging. With continued R&D, thereare many killer application opportunities for the 4G as well as technological challengies. We briefly listed

all the key technologies and protocols used in each generation of the mobile wireless communications in

th following table.

0G 0G refers to pre-cellular mobile telephony technology in 1970s. These mobile telephoneswere usually mounted in cars or trucks, though briefcase models were also made.

PTT Push to talk

MTS Mobile Telephone System

IMTS Improved Mobile Telephone Service

AMTS Advanced Mobile Telephone System

0.5G 0.5G is a group of technologies with improved feature than the basic 0G technologies.

Autotel/PALM Autotel, or PALM (Public Automated Land Mobile)

ARP Autoradiopuhelin, Car Radio Phone

HCMTS High Capacity Mobile Telephone System

1G 1G (or 1-G) is the first-generation wireless telephone technology, cellphones. These are

the analog cellphone standards that were introduced in the 1980s.

NMT Nordic Mobile Telephone

AMPS Advanced Mobile Phone System

TAGS Total Access Communication System (TACS) is the European version of AMPS.

JTAGS Japan Total Access Communication System
http://www.wirelesscommunication.nl/reference/chaptr06/randacc.htmhttp://www.wirelesscommunication.nl/reference/chaptr06/aloha/aloha.htmhttp://www.wirelesscommunication.nl/reference/chaptr06/aloha/aloha.htmhttp://www.wirelesscommunication.nl/reference/chaptr05/spreadsp/fh.htmhttp://www.wirelesscommunication.nl/reference/chaptr06/randacc.htmhttp://www.wirelesscommunication.nl/reference/chaptr06/aloha/aloha.htmhttp://www.wirelesscommunication.nl/reference/chaptr05/spreadsp/fh.htm


5/7

2G 2G (or 2-G) is the second-generation wireless telephone, which is based on digital

technologies. 2G networks is basically for voice communications only, except SMS

messaging is also available as a form of data transmission for some standards.

GSM Global System for Mobile Communications

iDEN Integrated Digital Enhanced Network

D-AMPS Digital Advanced Mobile Phone System based on TDMA

cdmaOne Code Division Multiple Access technology defined by IS-95

PDC Personal Digital Cellular

TDMA Time Division Multiple Access

2.5G 2.5G is a group of bridging technologies between 2G and 3G wireless communication. Itis a digital communication allowing e-mail and simple Web browsing, in addition to

voice.

GPRS General Packet Radio Service

WiDEN Wideband Integrated Dispatch Enhanced Network

2.75G 2.75G refer to the technologies which don't meet the 3G requirements but are marketedas if they do.

CDMA2000

1xRTT

CDMA-2000 is a TIA standard (IS-2000) that is an evolutionary outgrowth of cdmaOne.CDMA2000 with 1xRTT is slight weaker than 3G requirements.

EDGE Enhanced Data rates for GSM Evolution

3G 3G stand for the third generation of wireless communication technologies, which support

broadband voice, data and multi-media communications over wireless networks.

W-CDMA Wideband Code Division Multiple Access

UMTS Universal Mobile Telecommunications System

FOMA Freedom of Mobile Multimedia Access

CDMA2000

1xEV

More advanced CDMA2000 with 1xEV technology satisfy 3G requirements.

TD-SCDMA Time Division Synchronous Code Division Multiple Access

3.5G The 3.5G generally refer to the technologies beyond the well defined 3G wireless/mobile

technologies.

HSDPA High-Speed Downlink Packet Access

3.75G The 3.75G refer to the technologies beyond the well defined 3G wireless/mobile

technologies.

HSUPA High-Speed Uplink Packet Access

4G 4G is the name of technologies for high-speed mobile wireless communications designedfor new data services and interactive TV through mobile network.


6/7

3G: Third Generation Wireless Technologies and Services

Third Generation Wireless(3G) contains a group of standards to support broadband voice, data and multi-media communications over wireless networks. IMT-2000, the 3G standards developed by ITU, will

specify no less than five means of multiple access CDMA2000, WCMA, a time division duplex versionof WCDMA, 136HS (based on the UWCC's recommendation), and Digital Enhanced Cordless Telephone(DECT). The "family of standards" will be required to interoperate with both GSM MAP and IS-41

networks. Namely, the WCDMA specification will be required to allow interconnection with IS-41 and

CDMA2000 will be required to interface with GSM MAP.

Currently, the second generation (2G) of wireless networks, such as GSM, CDMA (IS-95) and TDMA(IS-136) networks, are widely used in the wireless communications. The 2G networks can provide narrow

band (up to 144kbps) voice and data services using circuit switching techniques. To conduct a smooth

evolution from the 2G to 3G wireless networks, some transitional technologies, such as GPRS for GSM,

136 high-speed for TDMA or IS-95B for CDMA, are defined, which are sometimes called 2.5G wireless

technologies.

The following table lists the comparison and evolution of Wireless Systems from 1G, 2G to 3G:

1G 2G 3G

System Analogue Digital Digital

Major

Systems

AMPS, NMT andTACS

GSM, CDMA and TDMAWCDMA, CDMA-2000 andTD-SCDMA

Application Voice Voice + little Circuit- switch Data Voice + Packet-switch Data

Local

Subscriber Less than 500k About 5.9M More than 5M (Estimated)

SpeedDepends on AnalogueSignal

9.6kbps - 14.4kbps384kbps for mobile & 2Mbpsfor stationary

Properties

Unstable, incomplete

coverage and poorsound quality

More secure, data services

available, broader coverage, more

stable, allow more user, bettersound quality

Multimedia data, positioning

capability, connection toInternet, always connected


7/7

3G: Third Generation Wireless Technologies and Services

Documents

Advanced Mobile Phone System