mobile communications (650539)...in the conventional mobile telephone systems (mts, imts-mj and...

Philadelphia University

Faculty of Engineering Communication and Electronics Engineering

Part 1 Dr. Omar R Daoud 1

MOBILE

COMMUNICATIONS

(650520)

10/10/2017 Dr. Omar R Daoud 2

Introduction

Mobile/ Wireless Systems

Transmit and/or Receive data between/among 2+

points in a distance without electrical conductor

connections between some/whole parts.

It is based on using the electromagnetic waves

Why?

Reach far distances without cables limitations

Optimize the systems at Low footprint

Adaptations ( (re)configuration)

Manage resources (Low cost)


Why Cellular Mobile Systems?

To Improve:

* Service Capability

* Service Performance

* Frequency Spectrum Utilization



Improving the Service Capability In a conventional mobile telephone system:

It is usually designed by selecting one or more channels from a

specific frequency allocation for use in autonomous

geographic zones.

Each zone is planned to be as large as possible (the

transmitted power must be as high as the federal specifications

allows).

The user must reinitiate the call when moving into a new zone

because the call will be dropped.

The number of active users is limited to the number of channels

assigned to a particular frequency zone.



Improving the Service Performance In the conventional mobile telephone systems (MTS, IMTS-

MJ and IMTS-MK) a total of 33 channels were allocated. The

large number of subscribers created a high blocking

probability during the busy hours. Thus a high-capacity

systems were needed



Improving the Frequency Spectrum Utilization In a conventional mobile telephone system the

frequency utilization measurement is defined as the maximum number of subscribers that could be served by one channel at the busy hour.

In such systems the channel can only serve one customer at a time in a whole area.

Thus, a new cellular system must be initiated to overcome these limitations. This systems must be: SSB: divides the allocated frequency band into maximum

numbers of channels

Cellular: reuses the allocated frequency band in different geographical locations

Spread-spectrum or Frequency-hopped: generates many codes over a wide frequency band

Introduction


Ubiquitous communication networks are the FUTURE

(people-to-people, people-to-devices and vice versa,

and devices-to-devices) Next-generation Cellular

Wireless Internet Access

Wireless Multimedia

Sensor Networks

Smart Homes/Spaces

Automated Highways

In-Body Networks

IoT


Introduction


Early Systems Marconi (late 1800s): Radio Link,

English Channel, over 18-miles

First World War, German military:

wireless phones on military trains

US(1934): amplitude modulation

(AM) mobile communication

systems for public safety.

Edwin Armstrong (1935): frequency

modulation (FM) for the first time.

Bell Labs (1946) had begun to offer

mobile telephone services on

vehicles


https://bebusinessed.com/history/history-cell-phones/


Mobile/ Wireless Systems Definitions

BS (Base Station): It is a fixed station, which is located on either the center or the edge of a coverage region. Consists of radio channels, transmitter and receivers antennas. It consists of radio channels, transmitting and receiving antennas.

MS (Mobile Station): A station, which is intended for use while in motion at unspecified location.

MSC (Mobile Switching Center): It coordinates the rooting of calls and connects the BSs and the MSs to the Public Switched Telephone Network (PSTN).

Forward Channel/ downlink: The transmission process from BS to MS.

Reverse Channel/ uplink: The transmission process from MS to BS.

Full Duplex: Transmission and reception on two different channels are allowed simultaneously.

Half Duplex: At any time the user can only transmit or receive information (Radio Taxi, walkie-talkies).

Simplex: Only one-way information-transmission (Paging).



Handoff: It is a process of automatically changing frequencies as the mobile unit moves into a different frequency zone. Thus, the call can be continued in a new frequency without redialing.

Hard Handoff: It is a process of assigning different radio channels during the hand off.

Soft Handoff: It is the ability to select between the instantaneous received signal from the available BSs.

Roaming: It is a MS operates in a service area different than that from which service has been subscribed.

FCC (Federal Communications Commission) It is an independent government organization that runs from the proceeds of regulatory fines in its regulation of radio, TV, wire and satellite communications.

CC( Control Channel): It is used for transmission of call setup, call request, call initiation and other purposes.

Page It is a brief message which is broadcast over the entire service area.


FDD (Frequency Division Duplexing): The radio transmission channels are provided simultaneously for the subscriber and the BS.

– Forward channel: base station to mobile user

– Reverse channel: mobile user to base station

TDD (Time Division Duplexing): A single radio channel can be shared in time between the subscriber and the BS.


Mobile/ Wireless Systems Examples

Paging Systems:

Conventional: Send brief messages to a subscriber.

Lately: New headlines, faxes…etc.

It making use of (simulcasting) simultaneous broadcasting for the paging message from BS to another.

It needs a large transmission power in order to cover the system area.



Cordless Telephone Systems:

It is a full duplex system.

Conventional: in-home use, few tens of meters distance

Lately: out-door use, combined to the paging systems, few hundred of meters per station distance.



Cellular telephone Systems:

Connected to the PSTN

Accommodates large number of users

Covers a wide geographical area

Limited BW ??? (cellular concept)

Needs A Common air interface (CAI)

Forward voice channel (FVC)

Reverse voice channel (RVC)

Forward control channels (FCC)

Reverse control channel (RCC)



Cellular telephone Systems:

Frequency modulation

Antenna diversity

Cellular concept Bell Labs (1957 & 1960)

Frequency reuse Typically every 7 cells

Handoff as caller moves

Modified Central Office switch HLR, paging, handoffs

Sectors improve reuse Every 3 cells possible


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Mobile/ Wireless Cellular Systems Standards

1G (Analog):

Late 1970s and early 1980s.

Evolved out of the growing number of mobile communications users.

Semiconductors and Microprocessors affect the size and the weight.

Based on analog communication systems:

FM modulations (no security, poor voice quality, large phone size)

Frequency Division Multiple Access technique (FDMA), single channel/user

(wasting the limited resources), limited capacity.

Hard Handoff (poor reliability)

900MHz Frequency range, 30 Channels, 30kHz BW each

Voice transmission Only. (not support for wireless data)

The channel is agreed with the serving BS before transmission takes place



1G (Analog) systems:



1G (Analog):

Advanced Mobile Phone Service (AMPS) US trials 1978; deployed in Japan (’79) & US (’83)

800 MHz band — two 20 MHz bands

Nordic Mobile Telephony (NMT) Scandinavian Countries (Launched 1979-1981)

450 MHz; later at 900 MHz (NMT900)

Total Access Communications System (TACS) British design; similar to AMPS; deployed 1985



2G (Digital):

Evolved out of the need to improve the speech quality, the system capacity, the coverage and the securities; i.e.1G drawbacks.

Based on GSM (Groupe Speciale Mobile, ETSI 1989, later changed to Global System for Mobile)

Based on digital communication systems. Digital Mobile phones (requires strong digital signals)

Digital modulation

Data compression

Error control

Soft Handoff

Time Division Multiple Access technique (TDMA), enhances the system capacity (8

users per 200KHz). In addition to Code DMA (CDMA).

Supports data, picture and multimedia services; such as SMS and MMS. (unable to

handle complex data such as videos)

Adopted in Frequency range; 900MHz, 1800MHz and 1900MHz.

Launched in Finland, 1991 (up to 64kbps)



2G (Digital) systems:

GSM (Supports 8 time slotted users for each 200KHz radio channel)

IS (Interm Standard)-54/ IS-136 North American TDMA; PDC (Pacific Digital cellular), Japan. (Supports 3 time slotted users for each 30KHz radio channel)

iDEN

DECT (Digital European Cordless Telephony) and PHS (Personal Handiphone Service)

IS-95 CDMA (cdmaOne) (supports 64 users tha are orthogonally coded and simultaneously Transmitted on each 1.25 MHz channel)



2G (Digital) systems:



2.5G:

2.5G is an interim solution designed to allow for improved data rates prior to 3G implementation.

A variety of 2.5G techniques are being employed to improve the speed of data for enhanced e-mail and Internet access.

Supports web browsing language called Wireless applications protocol (WAP) that allows standard web pages to be viewed in a compressed format.

A wide range of 2.5G standards have been developed to allow each of the major 2G technologies: GSM, CDMA and IS-136.



2.5G systems:

TDMA upgrade options for GSM carriers are

HSCSD (High speed circuit switched data), Up to 57.6 Kbps data-

rate.

GPRS (General Packet Radio Service), for IS-136, Up to 171.2 Kbps

data-rate

EDGE ( Enhanced data rates for GSM evolution ), for IS-136, Up to

384 Kbps data-rate

Evolution of CDMA Systems,

IS-95B, Up to 64 Kbps



3G:

Evolved out of the need to Simultaneous voice and data transmission

Interactive web sessions ( Multi-Mb internet access)

Multimedia Content (high resolution, such as live videos, video conferencing), +144kbps in all environments, 2Mbps in low mobility.

Based on the International Telecommunication Union (ITU) family of standards under the International Mobile Telecommunications-2000 (IMT-2000).

Enables greater network capacity and Improves the spectral efficiency.

IP architecture

New spectrum is allocated for these technology



3G:

Be supported by the network infrastructure of the WCDMA (UMTS) and the EDGE 2G systems (operates in different frequencies). UMTS (Universal Mobile Telecommunications System) or WCDM

(Wideband Code Division Multiple Access) was selected as the successor to GSM.

It is the European standard for 3G.

It utilizes one 5 MHz channel for both voice and data (data speeds up to 2 Mbps).

EDGE

It is a mobile network radio technology that allows current GSM networks to offer 3G services within existing frequencies.

It is upgrade to GPRS' data and GSM's voice networks (offers data speed three times that of GPRS).



3G systems:

CDMA system evaolved to CDMA2000

CDMA2000-1xRTT: Upto 307 Kbps

CDMA2000-1xEV:

CDMA2000-1xEVDO: upto 2.4 Mbps

CDMA2000-1xEVDV: 144 Kbps datarate

GSM, IS-136 and PDC evolved to W-CDMA (Wideband CDMA) (also called UMTS)

Up to 2.048 Mbps data-rates, Future systems 8Mbps, to be fully deployed by 2010-2015


CDMA

GSM

TDMA

PHS (IP-Based)

64 Kbps

GPRS

115 Kbps

CDMA 1xRTT

144 Kbps

EDGE

384 Kbps

cdma2000

1X-EV-DV

Over 2.4 Mbps

W-CDMA

(UMTS)

Up to 2 Mbps

2G

2.5G

2.75G 3G

1992 - 2000+2001+

2003+

1G

1984 - 1996+

2003 - 2004+

TACS

NMT

AMPS

GSM/

GPRS

(Overlay)

115 Kbps

9.6 Kbps

9.6 Kbps

14.4 Kbps

/ 64 Kbps

9.6 Kbps

PDC

Analog Voice

Digital Voice

Packet Data

IntermediateMultimedia

Multimedia

PHS

TD-SCDMA

2 Mbps?

9.6 Kbps

iDEN

(Overlay)

iDEN

Source: U.S. Bancorp Piper Jaffray

Migration To 3G



4G (MAGIC: Mobile multimedia, Any-where, Global mobility solution over, Integrated wireless and Customized services) or Mobile Broadband Everywhere:

Evolved out of the need to achieve Ultra broadband speeds. Targeted 100-1000Mbps, 10 times faster than 3G.

4G phones compatibility with the 3G networks

A spectrally efficient system

Huge datrate

Perfect connectivity

Global roaming

High quality service, security and privacy.

Based on WiMax by Clearwire (Sprint Nextel, HTC and Samsung), and LTE (Long Term Evolution) by Verizon.

Enables greater network capacity and Improves the spectral efficiency.

IP architecture

New spectrum is allocated for these technology

http://www.comlab.hut.fi/opetus/4210/presentations/16_wcdma_rnp.pdf



4G (MAGIC: Mobile multimedia, Any-where, Global mobility solution over, Integrated wireless and Customized services):

It will be designed based on OFDM (Orthogonal Frequency Division Multiplexing), adaptive processing and smart antennas.



4G (MAGIC: Mobile multimedia, Any-where, Global mobility solution over, Integrated wireless and Customized services):

LTE (late 2009 to the ITU-T and approved 2011): High speed data for mobile phones and data terminals

Supports at least 200 active data users/ 5MHz cell

Based on GSM/EDGE and UMTS/HSPA

Uses new modulation technology

Manages fast moving mobiles

Delivers services such as Mobile TV, 2Gbps datarates

Fast switching technology

Introduces multicarriers to use ultra wide bandwidth, up to 100MHz



3G and 4G Comparison:


Mobile Systems Revolutions



5G, late 2010s:

Evolved out of the need to support WWWW (Wireless World Wide Web)

No limitations, high speed, high capacity

Multimedia clarity, multimedia newspapers, TV programs,(HD Quality)

Larg mobile phone memory, dialing speed



4G and 5G Comparison:



5G, late 2010s:

mobile communications (650539)...in the conventional mobile telephone systems (mts, imts-mj and...

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