Chapter 5 Cellular Networks PDF

CHAPTER FIVE CELLULAR NETWORKS Compiled by Mikiyas A. Debark University LOGO Chapter Contents  Principles of Cellular Networks  First Generation (1G) Cellular and Paging Networks  Second Generation (2G) Cellular Networks  The 2.5G Cellular Networks ...

CHAPTER FIVE CELLULAR NETWORKS Compiled by Mikiyas A. Debark University LOGO Chapter Contents  Principles of Cellular Networks  First Generation (1G) Cellular and Paging Networks  Second Generation (2G) Cellular Networks  The 2.5G Cellular Networks  Third Generation (3G) Cellular Networks  Fourth Generation (4G) Cellular Networks  Overview of Fifth Generation (5G) Cellular Networks Page 2 LOGO Page 3  LOGO Principles of Cellular Networks WHAT is Cellular Network ?  A cellular network is a type of communication network that divides a geographic area into smaller regions known as cells.  Each cell is served by a base station, which provides wireless coverage and communication to mobile devices within that cell.  Cellular networks enable mobile devices (such as smartphones) to connect to the network for voice calls, text messages, and data transmission. Page 4 LOGO Cont. Page 5  LOGO Cont.  A cellular phone is a device that can make and receive telephone calls over a radio link despite the fact that moving around a wide geographic area  Modern mobile phones also support services such as:  Text messaging,  MMS (multimedia messaging services),  E-mail , Internet access, short-range wireless communications (infrared, Bluetooth),  applications, gaming and photography  The major component of the cell phone system is the cell. Page 6  LOGO Cont. Cellular Network Cells  The entire network coverage area is divided into cells based on the principle of frequency reuse.  A cell : basic geographical unit of a cellular network;  is the area around an antenna where a specific frequency range is used;  is represented graphically as a hexagonal shape, but in reality it is irregular in shape  when a subscriber moves to another cell, the antenna of the new cell takes over the signal transmission.  A cluster is a group of adjacent cells, usually 7 cells; no frequency reuse is done within a cluster.  The frequency spectrum is divided into sub-bands and each sub-band is used within one cell of the cluster. Page 7  LOGO Principles of Cellular Networks Cell Design  Cell design (around 10 mile radius)  Served by base station consisting of transmitter, receiver, and control unit.  Base station (BS) antenna is placed in high places (like tower, high rise buildings) -  Operators pay around money per month for BS  10 to 50 frequencies assigned to each cell  Cells set up such that antennas of all neighbours are equidistant (hexagonal pattern)  In North America, two 25-MHz bands allocated to AMPS (Advanced Mobile Phone System)  One for transmission from base to mobile unit  One for transmission fromPage mobile 8 unit to base  LOGO Principles of Cellular Networks Cell Design cont.  Cells are grouped into a cluster of seven  Letters indicate frequency use  To add more users, smaller cells (microcells) are used  Frequencies may not need to be different in CDMA (soft handoff). Page 9  LOGO Principles of Cellular Networks Types of cells  Femtocell: smallest unit of the hierarchy; – Covers only few meters where devices are in the physical range of the user. Sometimes called Home cell. Example WPANs.  Picocell: covers areas such as building or a tunnel; i.e. covers few tens of meters. Example. WLAN  Microcell: their coverage is small (half a mile in diameter) and are used in urban zones; low-powered transmitters and receivers are used to avoid interference with cells in another clusters.  Macrocell: their coverage is large (aprox. 6 miles in diameter); used in remote areas, high-power transmitters and receivers are used.  Megacell: national wide coverage. Sometimes it is called Satellite cell. Example. Satellite system Page 10  LOGO Principles of Cellular Networks Graphical representation of cell types Page 11  LOGO Principles of Cellular Networks Approaches to Increase Capacity  When we say approaches to increase capacity it deals with how to accommodate many users in a given cell.  Adding/reassigning channels which are not used.  Frequency borrowing: frequencies are taken from adjacent cells by congested cells.  In this case high traffic cells borrows channel from low traffic cells.  Cell splitting: cells in areas of high usage can be split into smaller cells. Page 12  LOGO Principles of Cellular Networks Frequency reuse  Frequency reuse refers to the use of similar frequency by two or more cells (which are not adjacent or in one cluster) for data transmission  It is a method used by service providers, to improve the efficiency of a cellular network and to serve millions of subscribers using a limited radio spectrum.  is based on the fact that after a distance a radio wave gets attenuated and the signal falls bellow a point where it can no longer be cause any interference.  a transmitter transmitting in a specific frequency range will have only a limited coverage area.  beyond this coverage area, that frequency can be reused by another transmitter.  However the cell must not be adjacent to avoid signal interference Page 13  LOGO Principles of Cellular Networks Services given by cellular networks are:  Voice communication  Data communication  Short Messaging Service (SMS)  Multimedia Messaging Service (MMS)  Global Positioning System (GPS)  etc… Page 14 LOGO Components Cellular Networks Page 15  LOGO Cont.  Mobile Station (MS) : This is basically the mobile phone  Base Transceiver Station (BTS): main component of a cell and it connects the subscribers to the cellular network; for transmission/reception of information it uses several antennas spread across the cell.  Base Station Controller (BSC): it is an interface between BTSs and linked to BTSs by cable or microwave links;  it routes calls between BTSs;  it is also connected to the MSC  Mobile Switching Center (MSC): the coordinator of a cellular network, it is connected to several BSCs, it routes calls between BSCs;  links the cellular network with other networks like PSTN through fiber optics, microwave or copper cable Page 16 LOGO Cont. Mobile Station Components Page 17  LOGO Call Processing in Cellular Network 1. Setting up a call process  when powered on, the phone does not have a frequency/ time slot/ assigned to it yet; so, it scans for the control channel of the BTS and picks the strongest signal.  then it sends a message (including its identification number) to the BTS to indicate its presence.  the BTS sends an acknowledgement message back to the cell phone.  the phone then registers with the BTS and informs the BTS of its exact location.  after the phone is registered to the BTS, the BTS assigns a channel to the phone and the phone is ready to receive or make calls 18 1/25/2025 Page 18  LOGO Call Processing in Cellular Network Cont. 2. Making a call process  the subscriber dials the receiver’s number and sends it to the BTS.  the BTS sends to its BSC the ID, location and number of the caller and also the number of the receiver.  the BSC forwards this information to its MSC.  the MSC routes the call to the receiver’s MSC which is then sent to the receiver’s BSC and then to its BTS.  then, communication with the receiver’s cell phone is established 19 1/25/2025 Page 19  LOGO Call Processing in Cellular Network Cont. 3. Receiving a call process  when the receiver’ phone is in an idle state it listens for the control channel of its BTS.  if there is an incoming call the BSC and BTS sends a message to the cells in the area where the receiver’s phone is located.  the phone monitors its message and compares the number from the message with its own.  if the numbers matches the cell phone sends an acknowledgement to the BTS.  after authentication, the communication is established between the caller and the receiver. 20 1/25/2025 Page 20  LOGO Hand off strategies  Handoff is the process of transferring ongoing call or data connectivity from one Base Station to another Base Station  The MSC (Mobile Switching Center) transfers the call to the new Base Station.  There are different types of handoff: Hard, Soft & Mobile assisted handoff  Hard Handoff: The previous connection breaks while switching from one cell to another  Soft Handoff: At least one of the links is kept before switching from one cell to another.  Mobile device is connected to both towers simultaneously for a brief period during the handoff process.  Mobile assisted handoff: In this technique, mobile devices assist the Base Station Controller (BSC) to transfer a call to another BSC  A mobile phone measures nearby signal qualities of all channels and 21 reports to the BSC for handoff management 1/25/2025 Page 21  LOGO Hand off strategies Multiple lower- power base stations that serve mobile users within their coverage area and handoff users to neighboring base stations as users move. 22 1/25/2025 Page 22  LOGO Interference and System capacity  Signal interference is the modification of a signal in a disruptive manner.  It may occur if neighbouring cells use the same radio frequencies  It may also be caused by natural substances in an environment.  As a result of interference, data may be lost.  Channels in a single cell may interfere one another due to improper configuration (adjacent channel interference) e.g. channels that have very closer frequencies  Co-channel cells that use the same frequency (frequency reuse), may interfere with each other unless they are separated by a minimum distance D ,where D=distance, N=cluster size, R=cell radius.  The cellular system capacity can be increased by frequency reuse technique 23  Signal interference should be avoided by distancing the co- 1/25/2025 channel cells Page 23  LOGO Global System for Mobile Communications (GSM)  Global System for Mobile Communications (GSM) is a second generation cellular standard developed to give voice services and data delivery using digital modulation. What makes GSM different from other networks?  Previous standard in cellular communication were restrictive.  GSM – global digital standard for cellular phones that offered roaming facility.  GSM operate in frequency bands: 900MHz, 1800 MHz, 1900 MHz  GSM provides voice and other data services. 24 1/25/2025 Page 24  LOGO GSM Overview  Formerly: Groupe Spéciale Mobile (founded 1982).  Now: Global System for Mobile Communications.  Developed by Pan-European standard (ETSI, European Telecommunications Standardization Institute).  Goal : was to provide a mobile phone system that allows users to roam throughout Europe and provides voice services compatible to other network systems.  Today many providers all over the world use GSM (219 countries in Asia, Africa, Europe, Australia, America)  more than 5 billion subscribers in more than 800 networks  more than 80% of all digital mobile phones use GSM 25 1/25/2025 Page 25  LOGO GSM Services Services given by GSM are:  Tele-services  Bearer or Data Services  Supplementary services 26 1/25/2025 Page 26  LOGO GSM Services cont. Tele-services  Telecommunication services that enable voice communication via mobile phones.  Offered services like  Mobile telephony.  Emergency calling 27 1/25/2025 Page 27  LOGO GSM Services cont. Bearer or Data Services  Include various data services for information transfer between GSM and other networks like PSTN, etc. at rates from 300bps to 9600bps.  Short Message Service (SMS)  up to 160 character alphanumeric data transmission to/from the mobile terminal  Faxing services  Voice mailbox  Electronic mail 28 1/25/2025 Page 28  LOGO GSM Services cont. Supplementary services  Call related services :  Call Waiting- Notification of an incoming call while on the handset.  Call Hold- Put a caller on hold to take another call.  Call Barring- All calls, outgoing calls, or incoming calls.  Call Forwarding- Calls can be sent to various numbers defined by the user.  Multi Party Call Conferencing - Link multiple calls 29 together. 1/25/2025 Page 29  LOGO Performance Characteristics of GSM Comparing to First generation Network  Communication  mobile, wireless digital communication; support for voice and data services  Total mobility  international access, chip-card enables use of access points of different providers  Worldwide connectivity  High capacity  better frequency efficiency, smaller cells, more customers per cell  High transmission quality  high audio quality  uninterrupted phone calls at higher speeds (e.g., from cars, trains) – better handoffs and  Security functions 1/25/2025 30  access control, authentication via chip-card and PIN Page 30  LOGO GSM Architecture 31 1/25/2025 Page 31  LOGO GSM Architecture cont. 32 1/25/2025 Page 32  LOGO GSM Architecture cont. 1. Mobile Station (MS) Subscriber Identity Module (SIM) Mobile Equipment (ME) 2 Base Station Subsystem (BSS) Base Transceiver Station (BTS) Base Station Controller (BSC) 3 Network Switching Subsystem(NSS) Mobile Switching Center (MSC) Home Location Register (HLR) Visitor Location Register (VLR) Authentication Center (AUC) Equipment Identity Register (EIR) 33 1/25/2025 Page 33  LOGO GSM Architecture cont. Mobile Station (MS)  is a device which is composed of all users equipment and software needed for communication with a mobile network.  is made up of two entities:  Subscriber Identity Module (SIM)  Mobile Equipment (ME) 1. Subscriber Identity Module (SIM) card  SIM – Smart card contains the International Mobile Subscriber Identity (IMSI).  SIM – a memory card (integrated circuit) holding identity information, phone book etc.  Allows user to send and receive calls and receive other subscribed services.  Protected by a password or PIN.  Can be moved from phone to phone – contains key information to activate the 34 phone 1/25/2025 Page 34  LOGO GSM Architecture cont. International Mobile Subscriber Identity (IMSI) key  IMSI – an n-digit unique number provided by the service provider and incorporated in the SIM card which identifies the subscriber.  IMSI enables a service provider to link a phone number with a subscriber  first 3 digits of the IMSI are the country code.  Example. Phone number “ +251917111213 ”  country code (CC)……… (+251) Ethiopia.  Service provider (SP) ……..(9) EthioTelecom  National Destination code(NDC)…. ( 917 ) Naqamtee.  Subscriber number (SN)………………..(111213) individual. 35 1/25/2025 Page 35  LOGO GSM Architecture cont. Temporary Mobile Subscriber Identity (TMSI) key  TMSI – is a temporary number, shorter than the IMSI, assigned by the service provider to the phone on a temporary basis.  TMSI key identifies the phone and its owner in the cell it is located; when the phone moves to a different cell it gets a new TMSI key.  as TMSI keys are shorter than IMSI keys they are more efficient to send.  TMSI key are used for securing GSM networks. International Mobile Equipment Identity (IMEI) key  IMEI – a unique 15 digit number identifying each phone, is incorporated in the cellular phone by the manufacturer.  IMEI ex.: 994456245689001  the IMEI is located on a white sticker/label under the battery, but it can also be displayed by typing *#06# on the phone. 36 1/25/2025 Page 36  LOGO GSM Architecture cont. 2. Mobile Equipment  Portable, vehicle mounted, hand held device.  Uniquely identified by an IMEI (International Mobile Equipment Identity).  Voice and data transmission  Monitoring power and signal quality of surrounding cells for optimum handover  Power level : 0.8W – 20 W  160 character long SMS. 37 1/25/2025 Page 37  LOGO GSM Architecture cont. Base Station Subsystem  is composed of two parts that communicate across the standardized interface allowing operation between components made by different suppliers. 1. Base Transceiver Station (BTS)  It is main component of a cell and it connects the subscribers to the cellular network.  communicates with Mobile station and BSC.  Encodes, encrypts, multiplexes, modulates and feeds the RF signals to the antenna. 2. Base Station Controller (BSC)  it is an interface between BTSs and it is linked to BTSs by cable or microwave links.  it routes calls between BTSs; it is also connected to the MSC  It communicates with MSC and BTS. 38 Manages Radio resources for BTS. 1/25/2025  Assigns Frequency and time slots for all MS’s in its area. Page 38  LOGO GSM Architecture cont. Network Switching Subsystem (NSS) 1. Mobile Switching Center (MSC) – the coordinator of a cellular network.  Heart of the network, & it is connected to several BSCs.  it routes calls between BSCs, & Billing information and collection.  links the cellular network with other networks like PSTN through fiber optics, microwave or copper cable. 2. Home Location Register (HLR) - is a database maintained by the service provider containing permanent data about each subscriber. 3. Visitor Location Register (VLR) – database that stores temporary data about a subscriber. 4. Authentication Center (AUC) – Protects against intruders in air interface.  Maintains authentication keys and algorithms and provides security.  Generally associated with HLR 5. Equipment Identity Register (EIR) – database located near the MSC and 39 containing information identifying cell phones. Page 39  LOGO GSM Architecture cont.  Generally, the architecture of GSM are organized from: 1. Mobile Station, 2. Base Station Subsystem, and 3. Network Subsystem.  There is one BTS per cell.  One BSC can control multiple BTS.  BSC:  allocates radio channels among BTSs.  Manages call handoffs between BTSs.  Mobile Switching Center (MSC) connects to PSTN and switches calls between BSCs. Provides mobile registration, location, authentication. Contains Equipment Identity Register. 40 1/25/2025 Page 40  LOGO GSM Architecture cont.  Home Location Register (HLR) and Visitor Location Register (VLR) provide call routing and roaming.  VLR + HLR + MSC functions are generally in one equipment.  Equipment Identity Register (EIR) contains a list of all valid mobiles.  Authentication Center (AuC) stores the secret keys of all SIM cards; used to protect user identity and data transmission.  Each handset has an International Mobile Equipment Identity (IMEI) number. You can get the IMEI of your device by dialing *#06#. 41 1/25/2025 Page 41 LOGO Page 42  LOGO Handover in GSM  Handover – moving a call from one cell to another cell due to subscriber’s mobility.  Changing the point of connection while communicating.  A situation that occurs when mobile station switches from one radio resources to another set. Types of handover  Hard Handover – old connection is broken before new connection is activated.  Soft Handover – new connection is activated before the old one is broken. 43 Page 43  LOGO GSM Roaming  Roaming – allowing the subscriber to send/receive calls outside the service provider’s coverage area.  The ability for a cellular customer to automatically make and receive voice calls, send and receive data, or access other services when travelling outside the geographical coverage area of the home network, by means of using a visited network.  Roaming Agreements between network operators required.  National Roaming(visited network in the same country as the home network).  International Roaming(visited network is outside the home country). 44 Page 44  LOGO GSM Security 1. Personal Identification Number (PIN)  the PIN is stored on the SIM card of the cell phone.  when the cell phone is turned on, the SIM checks the PIN; in case of 3 consecutive faulty PIN inputs a PUK (Personal Unblocking Key) is asked for.  in case of 10 faulty PUK inputs, the SIM is locked and the subscriber must ask a new SIM.  this security measure is within the cell phone and the service provider is not involved. 2. User Authentication  a mechanism for encrypting messages in a GSM network  the network sends random data to the cell phone (RAND)  each cell phone is allocated a secret key (KI)  using RAND and KI and the A3 encryption algorithm the cell phone generates a signed result (SRES) which is then sent to the network  a similar process takes place in the network which generates a signed result specific to the cell phone 45 the network compares its SRES with the SRES generated by the phone and in1/25/2025 case of a match the cell phone is connected to the network Page 45  LOGO GSM Security cont. 3. TMSI-Key Based Security  is most used in a GSM cellular network  a TMSI key provides a temporary identification to a cell phone and is provided by the network upon authentication  a TMSI key keeps changing according to the location of the cell phone  the mapping between IMSI and TMSI keys is handled by the VLR  IMSI are used only when the SIM is used for the first time. 46 1/25/2025 Page 46  LOGO General Packet Radio Service (GPRS) Network Constraints with existing GSM network  Data Rates too slow – about 9.6 kbps  Connection setup time too long  Inefficient resource utilization for busty traffic/high bandwidth transmission over short period  Proves expensive for busty traffic utilization  No efficient method for packet transfers 47 1/25/2025 Page 47  LOGO GPRS  GPRS (General Packet Radio Service) is a mobile data service available to users of GSM mobile phones.  It is often described as “2.5G”.  GPRS ≡ Mobile Internet  GPRS is a new bearer service for GSM that greatly improves and simplifies wireless access to packet data networks  GPRS applies packet radio principal to transfer user data packets in an efficient way b/w MS & external packet data network  It provides moderate speed data transfer, by using unused TDMA channels in the GSM network.  The theoretical limit for packet switched data is 171.2 kbit/s. 48 1/25/2025 Page 48  LOGO Comparison of GSM & GPRS 49 1/25/2025 Page 49  LOGO GPRS Objectives  Enable access to company LAN and the Internet  Provide reasonably high data rates  Enable the subscriber to be reachable at all times – not only for telephone calls but also for information such as new emails or latest news  Offer flexible access, either for many subscribers at low data rates or few subscribers at high data rates in order to optimize network usage  Offer low cost access to new services 50 1/25/2025 Page 50  LOGO GPRS Advantages  Efficient – GPRS mobile devices only use the GSM network when data is transferred.  Fast – GPRS gives speeds of up to 5 time faster than GSM.  Payment based on data usage – Billing is not based on time, but on the amount of data actually transferred. 51 1/25/2025 Page 51  LOGO Salient Features of GPRS  Important step on the path to 3G  GPRS is an overlay network over the GSM  Provides Data Packet delivery service  Support for leading internet communication protocols  Billing based on volume of data transferred  Utilizes existing GSM authentication and privacy procedures. 52 1/25/2025 Page 52  LOGO GPRS system architecture  GPRS’s packet data network is overlaid on the GSM network. However, it has  packet data channels  packet data switching and  transport network are different from that of GSM. 53 1/25/2025 Page 53  LOGO GPRS system architecture 54 1/25/2025 Page 54  LOGO GPRS system architecture  GSM Network  Not able to transmit data in packet switched mode  Three additional logical components to the existing GSM network  GPRS registers (GR)  Gateway GPRS support node (GGSN)  Serving GPRS support node (SGSN) 55 1/25/2025 Page 55  LOGO GPRS system architecture  The serving GPRS support node (SGSN): is responsible for routing the packet switched data to and from the mobile stations (MS) within its area of responsibility.  The gateway GPRS support node (GGSN): acts as interface between the GPRS backbone and the external packet data network (PDN).  The GPRS Register (GR): serve as databases that store subscriber-related information necessary for GPRS service provision.  These registers maintain information such as subscriber profiles, location updates, authentication data, and mobility management details.  It provides other additional function which is not available in 56 1/25/2025 GSM. Page 56 LOGO Cellular Network Generations (1G – 5G) Page 57  LOGO 1G TECHNOLOGY 1G refers to the first generation of wireless telephone technology, mobile telecommunications which was first introduced in 1980s and completed in early 1990s. It's Speed was upto 2.4kbps. It allows the voice calls in 1 country. 1G network use Analog Signal. AMPS (Advanced Mobile Phone System) was first launched in USA in 1G mobile systems. Page 58 LOGO DRAWBACKS OF 1G Poor Voice Quality Poor Battery Life Large Phone Size No Security Limited Capacity Poor Handoff Reliability 1G Wireless System Page 59  LOGO 2G TECHNOLOGY  2G technology refers to the 2nd generation which is based on GSM.  It was launched in Finland in the year 1991.  2G network use digital signals.  It’s data speed was upto 64kbps. Features Includes:  It enables services such as text messages, picture messages and MMS (multi media message).  It provides better quality and capacity than 1G. Page 60  LOGO DRAWBACKS OF 2G  2G requires strong digital signals to help mobile phones work. If there is no network coverage in any specific area , digital signals would weak.  These systems are unable to 2G Wireless System handle complex data such as Videos. Page 61  LOGO 2.5G TECHNOLOGY  2.5G is a technology between the second (2G) and third (3G) generation of mobile telephony.  2.5G is sometimes described as 2G Cellular Technology combined with GPRS. Features Includes:  Phone Calls  Send/Receive E-mail Messages  Web Browsing  Speed : 64-144 kbps  Camera Phones  Take a time of 6-9 mins. to download a 3 mins. Mp3 song Page 62  LOGO 3G TECHNOLOGY 3G technology refer to third generation which was introduced in year 2000s. Data Transmission speed increased from 144kbps- 2Mbps. Typically called Smart Phones and features increased its bandwidth and data transfer rates to accommodate web-based applications and audio and video files.  UMTS (Universal Mobile Telecommunications System) is the technology Page 63  LOGO FEATURES OF 3G TECHNOLOGY  Providing Faster Communication  Send/Receive Large Email Messages  High Speed Web / More Security Video Conferencing / 3D Gaming  TV Streaming/ Mobile TV/ Phone Calls  Large Capacities and Broadband Capabilities  11 sec – 1.5 min. time to download a 3 min Mp3 song. Page 64  LOGO DRAWBACKS OF 3G TECHNOLOGY  Expensive fees for 3G Licenses Services  It was challenge to build the infrastructure for 3G  High Bandwidth Requirement  Expensive 3G Phones.  Large Cell Phones Page 65 LOGO 4G TECHNOLOGY (Anytime ,Anywhere) Page 66  LOGO 4G TECHNOLOGY (Anytime, Anywhere) 4G technology refer to or short name of fourth Generation which was started from 2010s. Capable of providing 100Mbps – 1Gbps speed. One of the basic term used to describe 4G is MAGIC. MAGIC: Mobile Multimedia Anytime Anywhere Global Mobility Support Integrated Wireless Solution Customized Personal Services Also known as Mobile Broadband Everywhere. Page 67  LOGO 4G (Anytime, Anywhere) The next generations of wireless technology that promises higher data rates and expanded multimedia services. Capable to provide speed 100Mbps-1Gbps. High QOS and High Security Provide any kind of service at any time as per user requirements, anywhere. Features Include:  More Security  High Speed  High Capacity  Low Cost Per-bit etc. Page 68  LOGO DRAWBACKS OF 4G Battery uses is more Hard to implement Need complicated hardware Expensive equipment required to implement next generation network. Page 69  LOGO COMPARISON BETWEEN 3G Vs 4G The basic difference between 3G and 4G is in data transfer and signal quality. Technology 3G 4G Data Transfer Rate 3.1 MB/sec 100 MB/sec Internet Services Broadband Ultra Broadband Mobile - TV Resolution Low High Bandwidth 5-20 MHz 100MHz Frequency 1.6-2 GHz 2-8 GHz Download and upload 5.8 Mbps 14 Mbps Page 70  LOGO Countries with 4-G Firstly started in Except for the Scandinavian Countries (Northern Europe including Denmark and two of the nations of Scandinavian , Norway and Sweden. ), a few countries have started the 4G commercially. In the US, Sprint Nextel and Others Germany , Spain, China , Japan and England are also using the 4G services and mobiles. Page 71 LOGO WIRLESS MODELS OF 3G & 4G  3G WIRELESS SYSTEM  4G WIRELESS SYSTEM Page 72  LOGO 5G TECHNOLOGY 5G technology refer to short name of fifth Generation which was started from late 2020s. Complete wireless communication with almost no limitations. It is highly supportable to WWWW (Wireless World Wide Web). Page 73  LOGO BENEFITS OF 5G TECHNOLOGY High Speed, High Capacity 5G technology providing large broadcasting of data in Gbps Multi - Media Newspapers, watch T.V programs with the clarity as to that of an HD Quality. Faster data transmission that of the previous generations. Large Phone Memory, Dialing Speed, clarity in Audio/Video. Support interactive multimedia , voice, streaming video, Internet and other 5G is More Effective and More Attractive. Page 74  LOGO COMPARISON BETWEEN 4G Vs 5G The following basic differences between 4G and 5G are: Page 75 LOGO EVOLUTION OF 1G TO 5G TECHNOLOGY Page 76  LOGO WIRELESS APPLICATIONS Wireless applications are those which we use free space as the transmission medium & do not involve cabling like fiber or copper cables. Page 77  LOGO WIRELESS SERVICES Wireless solution for: Business and Industry Schools , Colleges Doctors , Pilots Police and Vehicles etc. Page 78  LOGO CONCLUSION All totally the best way to help all users is to use 5G as the next wireless system and in totally it is safety and secure for public, this the need that demands the solution. Today’s wired society is going wireless and if it has problem, 5G is answer. 5G technology is going to give tough competition to Computers and Laptops. It was available in the market 2020 at affordable cost with more reliability than previous mobiles.(in some cities Ethiopia start 5G.) Page 79  CONCLUSION dddfff