Mobile computing technology enables wireless transmission of data, voice, and video between devices without physical connections, allowing users to communicate from remote locations. The document covers mobile communication frameworks, mobile hardware and software, applications, issues, and challenges including mobility, wireless mediums, and portability. It also details wireless telephony concepts like cellular networking, UMTS, and GSM, including their structures, features, advantages, and disadvantages.

1. Mobile Computing UNIT 1
BY:SURBHI SAROHA

2. SYLLABUS
• Introduction,
• issues and challenges in mobile computing,
• overview of wireless telephony: cellular concept,
• UMTS,
• GSM: air-interface,
• channel structure,
• location management: HLR-VLR,
• hierarchical,
• handoffs,

3. CONT…..
• policy based handoff process,
• channel allocation in cellular systems,
• CDMA,
• GPRS.

4. Introduction
• Mobile Computing is a technology that provides an environment that
enables users to transmit data from one device to another device without
the use of any physical link or cables.
• In other words, you can say that mobile computing allows transmission of
data, voice and video via a computer or any other wireless-enabled device
without being connected to a fixed physical link. In this technology, data
transmission is done wirelessly with the help of wireless devices such as
mobiles, laptops etc.
• This is only because of Mobile Computing technology that you can access
and transmit data from any remote locations without being present there
physically. Mobile computing technology provides a vast coverage diameter
for communication. It is one of the fastest and most reliable sectors of the
computing technology field.

5. The concept of Mobile Computing can be
divided into three parts:
• Mobile Communication
• Mobile Hardware
• Mobile Software

6. Mobile Communication
• Mobile Communication specifies a framework that is responsible for the
working of mobile computing technology.
• In this case, mobile communication refers to an infrastructure that ensures
seamless and reliable communication among wireless devices.
• This framework ensures the consistency and reliability of communication
between wireless devices.
• The mobile communication framework consists of communication devices
such as protocols, services, bandwidth, and portals necessary to facilitate
and support the stated services.
• These devices are responsible for delivering a smooth communication
process.

7. Mobile communication can be divided in the
following four types:
• Fixed and Wired
• Fixed and Wireless
• Mobile and Wired
• Mobile and Wireless

9. Mobile communication can be divided in the
following four types:
• Fixed and Wired: In Fixed and Wired configuration, the devices are fixed at a position,
and they are connected through a physical link to communicate with other devices.
• For Example, Desktop Computer.
• Fixed and Wireless: In Fixed and Wireless configuration, the devices are fixed at a
position, and they are connected through a wireless link to make communication with
other devices.
• For Example, Communication Towers, WiFi router
• Mobile and Wired: In Mobile and Wired configuration, some devices are wired, and
some are mobile. They altogether make communication with other devices.
• For Example, Laptops.
• Mobile and Wireless: In Mobile and Wireless configuration, the devices can
communicate with each other irrespective of their position. They can also connect to any
network without the use of any wired device.
• For Example, WiFi Dongle.

10. Mobile Hardware
• Mobile hardware consists of mobile devices or device components
that can be used to receive or access the service of mobility.
• Examples of mobile hardware can be smartphones, laptops, portable
PCs, tablet PCs, Personal Digital Assistants, etc.
• These devices are inbuilt with a receptor medium that can send and
receive signals.
• These devices are capable of operating in full-duplex. It means they
can send and receive signals at the same time.
• They don't have to wait until one device has finished communicating
for the other device to initiate communications.

11. Mobile Software
• Mobile software is a program that runs on mobile hardware.
• This is designed to deal capably with the characteristics and
requirements of mobile applications.
• This is the operating system for the appliance of mobile devices.
• In other words, you can say it the heart of the mobile systems.
• This is an essential component that operates the mobile device.

12. Applications of Mobile Computing
• Following is a list of some significant fields in which mobile computing
is generally applied:
• Web or Internet access.
• Global Position System (GPS).
• Emergency services.
• Entertainment services.
• Educational services.

13. Issues and challenges in mobile computing
• Mobile Computing is defined as a computing environment which is
mobile and moves along with the user.
• There are various number of challenges that affected mobile
computing and it has to overcome them.
• Some of the major technical challenges faced by mobile computing
are:
• 1. Mobility
• 2. Wireless Medium
• 3. Portability

14. 1. Mobility:
• It is the most important aspect of mobile computing, but it has to face the
certain challenges which are :
• Auto configuration of the system, as the environment of the system is developing
continuously. Hence for every change, it has to configure itself to the new
situation.
• Location management is also a big objection in mobility. To manage the location,
following tasks are to be performed regularly over a fixed period of time.
• Track user’s call.
• Update user’s position and data.
• To maintain the heterogeneity is also a big task as the system is keep moving in a
large variation of situations
• Range of spectrum.
• Verification of security.

15. 2. Wireless Medium:
• The transmission medium in mobile computing is wireless, therefore
the following points are considered:
• Various interferences occurs in the mobile computing by the different
elements in the environment.
• Accuracy and quantity of bandwidth should be sufficient.
• Network cost is feasible.

16. 3. Portability:
• This means that the communication device moves, for eg. mobile
phones.
• The following mobile constraints are to be considered as the devices
are also mobile:
• Minimum number of resources are used.
• Security is very less, as security risks include the processing of fake
transactions, unauthorized access of data and program files, and the
physical theft or damage of the device.
• Restrictions of the battery.

17. overview of wireless telephony: cellular
concept
• Cellular Approach
• With limited frequency resource, cellular principle can serve
thousands of subscribers at an affordable cost. In a cellular network,
total area is subdivided into smaller areas called “cells”. Each cell can
cover a limited number of mobile subscribers within its boundaries.
Each cell can have a base station with a number of RF channels.
• Frequencies used in a given cell area will be simultaneously reused at
a different cell which is geographically separated. For example, a
typical seven-cell pattern can be considered.

19. CONT…..
• Total available frequency resources are divided into seven parts, each part
consisting of a number of radio channels and allocated to a cell site. In a
group of 7 cells, available frequency spectrum is consumed totally. The
same seven sets of frequency can be used after certain distance.
• The group of cells where the available frequency spectrum is totally
consumed is called a cluster of cells.
• Two cells having the same number in the adjacent cluster, use the same set
of RF(Radio Frequency) channels and hence are termed as “Co-channel
cells”. The distance between the cells using the same frequency should be
sufficient to keep the co-channel (co-chl) interference to an acceptable
level. Hence, the cellular systems are limited by Co-channel interference.

20. Hence a cellular principle enables the
following.
• More efficient usage of available limited RF source.
• Manufacturing of every piece of subscriber's terminal within a region
with the same set of channels so that any mobile can be used
anywhere within the region.

21. UMTS
• UMTS or Universal Mobile Telecommunications Framework, is the
3G successor to the GSM family of measures counting GPRS and
EDGE.
• 3G UMTS employments a completely diverse radio interface based
around the utilize of Coordinate Grouping Spread Range as CDMA or
Code Division Multiple Access.
• Although 3G UMTS employments a completely distinctive radio get to
standard, the center arrange is the same as that utilized for GPRS and
EDGE to carry partitioned circuit exchanged voice and bundle data.

22. CONT…..
• UMTS employments a wideband adaptation of CDMA possessing a 5 MHz
wide channel.
• Being more extensive than its competition CDMA2000 which as it was
utilized a 1.25MHz channel, the tweak conspire was known as wideband
CDMA or WCDMA/W-CDMA.
• This title was regularly utilized to allude to the total framework.
• It could be a frame of media transmission utilized for remote gathering and
transmission.
• It is an advancement in speed boost from the more seasoned 2G standard
of transmission speed and can increment information transmission times
between gadgets and servers.

23. UMTS Applications
• Streaming / Download (Video, Audio)
• Videoconferences.
• Fast Internet / Intranet.
• Mobile E-Commerce (M-Commerce)
• Remote Login
• Background Class applications
• Multimedia-Messaging, E-Mail
• FTP Access
• Mobile Entertainment (Games)

24. Features of UMTS
• UMTS could be a component of IMT-2000 standard of the Universal
Broadcast communications Union (ITU), created by 3GPP.
• It employments wideband code division multiple access (W-CDMA) discuss
interface.
• It gives transmission of content, digitized voice, video and multimedia.
• It gives tall transmission capacity to portable operators.
• It gives a tall information rate of 2Mbps.
• For High-Speed Downlink Parcel Get to (HSDPA) handsets, the data-rate is
as tall as 7.2 Mbps within the downlink connection.
• It is additionally known as Flexibility of Mobile Multimedia Access (FOMA).

25. Advantages of UMTS
• UMTS could be a successor to 2G based GSM advances counting GPRS and
EDGE . Gaining a 3rd title 3GSM since it could be a 3G relocation for GSM
• Support 2Mbit/s information rates.
• Higher Information rates at lower incremental costs.
• Benefits of programmed universal wandering also necessarily security and
charging capacities, permitting administrators emigrate from 2G to 3G
whereas holding numerous of their existing back-office frameworks
• Gives administrators the adaptability to present unused mixed media
administrations to trade clients and buyers
• This not as it were gives client a valuable phone but moreover deciphers
higher incomes for the administrator.

26. Disadvantages of UMTS
• It is more expensive than GSM.
• Universal Mobile Telecommunication System has poor video
experience.
• Universal Mobile Telecommunication System still not broadband.

27. GSM: air-interface
• GSM (Global System for Mobile Communication) is a digital mobile
network commonly utilized by mobile phone users in Europe and
around the world.
• GSM, the most popular of the three digital wireless telephony
systems (TDMA, GSM, and CDMA), is a version of time division
multiple access (TDMA).
• GSM converts and compresses data before sending it along a channel
with two other streams of user data, each with its time slot.

28. What is GSM?
• GSM stands for Global System for Mobile Communication.
• GSM is an open and digital cellular technology used for mobile
communication.
• It uses 4 different frequency bands 850 MHz, 900 MHz, 1800 MHz,
and 1900 MHz.
• It uses the combination of FDMA and TDMA.

29. GSM is having 4 different sizes of cells
• Macro: In this size of the cell, a Base Station antenna is installed.
• Micro: In this size of cell, antenna height is less than the average roof
level.
• Pico: Small cells’ diameter of a few meters.
• Umbrella: It covers the shadowed (Fills the gaps between cells)
regions.

30. Features of GSM
• Supports international roaming.
• Clear voice clarity.
• Ability to support multiple handheld devices.
• Spectral / frequency efficiency
• Low powered handheld devices.
• Ease of accessing network
• International ISDN compatibility.
• Low service cost.
• New features and services.

31. The Architecture of GSM
• BSS : BSS stands for Base Station Subsystem. BSS handles traffic and
signaling between a mobile phone and the network switching
subsystem. BSS having two components BTS and BSC.
• NSS : NSS stands for Network and Switching Subsystem. NSS is the
core network of GSM. That carried out call and mobility management
functions for mobile phone present in network. NSS have different
components like VLR, HLR and EIR.
• OSS : OSS stands for Operating Subsystem. OSS is a functional entity
which the network operator monitor and control the system. OMC is
the part of OSS. Purpose of OSS is to offer the customer cost-effective
support for all GSM related maintenance services.

32. How Does GSM Work?
• GSM is a globally recognised digital cellular communication protocol.
• The GSM standard was developed by the European Telecommunications Standards
Institute to describe the procedures for second-generation digital mobile networks, such
as those used by mobile phones.
• It is a broad-area communications technology programme that uses digital radio
channelling to provide audio, information, and multimedia communication systems.
• Every GSM radio channel is 200 kHz broad and is further divided into frames of eight
time slots.
• The GSM system consists of mobile stations, base stations, and interweaving switching
systems.
• The GSM programme allows 8 to 16 audio users to share a single radio channel, and each
radio transmission station can have numerous radio channels.
• Because of its simplicity, cost, and accessibility, GSM is now the most often utilised
network technology in the Internet of Things (IoT).

34. Applications of GSM
• Mobile Telephony
• VoIP(Voice over Internet Protocol) Integration
• SMS (Short Message Service)
• Mobile Banking
• Smart Home Systems
• Telemedicine
• Surveillance Systems
• Alarm System
• Cell Broadcasting

35. Advantages of GSM
• Compatibility: GSM is widely used around the world, so it is compatible
with many different networks and devices.
• Security: GSM offers enhanced security features such as authentication,
encryption and confidentiality, which helps to protect the user’s privacy
and data.
• Efficient use of bandwidth: GSM uses a time-division multiplexing
(TDM) technique which enables many users to share the same frequency
channel at different times, making it an efficient use of the available
bandwidth.
• Roaming: GSM allows users to roam internationally and use their mobile
phones in other countries that use the same GSM standard.
• Wide range of features: GSM supports a wide range of features, including
call forwarding, call waiting, voicemail, conference calling, and more.

36. Disadvantages of GSM
• Limited coverage: GSM networks may have limited coverage in some
remote areas, which can make it difficult for users to make calls or access
the internet.
• Network congestion: GSM networks may become congested during peak
hours, which can lead to dropped calls or poor call quality.
• Security vulnerabilities: Although GSM offers enhanced security features,
it is still vulnerable to certain types of attacks, such
as eavesdropping and spoofing.
• Data transfer speed: GSM networks offer relatively slow data transfer
speeds compared to newer technologies such as 3G and 4G.
• Limited capacity: GSM networks have a limited capacity for handling large
volumes of data, which can be a disadvantage for users who require high-
speed internet access or other data-intensive applications.

37. Channel Structure
• Channel structure is the division and coordination of a communication
channel (information transfer) into logical channels, frames (groups) of
data, and fields within the frames that hold specific types of information.
• Each CDMA communication channel is composed of a radio channel pairs.
• A channel pair is composed of one forward channel (base station to mobile
device) and a reverse channel (mobile device to the base station).
• Each coded traffic channel is divided into 20 msec frames and each 20
msec frames are divided into 1.25 msec time slots. These time slots are
called power control groups.

38. Channel structure in GSM:

39. location management: HLR-VLR
• As From the Name VLR means Visitor Location Register and HLR means Home Location
Register so HLR having all detail of subscriber and VLR having temporary details for
mainly call processing related. Let’s check in detail HLR and VLR in Function in telecom.
• Home Location Register (HLR) – Main Location of All Database
• HLR Full Form – Home Location Register in telecom
• Home Location Register – HLR in gsm is main database which save all permanent
information about subscriber for network which having billing details, subscriber identity,
current status in network and many more for all type of technology either 2g, 3g, 4g or
5g.
• The HLR in telecom is the reference database for subscriber parameters. Actually HLR
Having all the detail like customer ID, customer number, billing detail and for prepaid
with IN intelligent network.
• It has detail of current recharge of prepaid user so far its is very complex but i just make
it in simple word for you.

40. Cont….
• Various identification numbers and addresses are stored, as well as
authentication parameters. This information is entered into the database
by the network provider when a new subscriber is added to the system.
• The HLR in telecom database contains the master database of all the
subscribers to a GSM PLMN.
• The data it contains is remotely accessed by all the MSCs and the VLRs in
the network and, although the network may contain more than one HLR,
there is only one database record per subscriber – each HLR is therefore
handling a portion of the total subscriber database.
• The subscriber data may be accessed by either the IMSI or the MSISDN
number.
• The data can also be accessed by an MSC or a VLR in gsm in a different
PLMN, to allow inter-system and inter-country roaming.

41. HLR in telecom
• HLR (Home Location Register) is a database that contains various
information about all mobile subscribers in a cellular network,
• e.g. B. the cell phone numbers, services, whether the numbers have
been ported to another network, and similar information.

42. list of data stored in HLR

43. Visitor Location Register (VLR in telecom) –
Location of Temporary Database – Instance Access
data
• VLR Full Form in telecom- Visitor Location Register
• Visitor Location Register – VLR is temporary database which save
temporary information about subscriber like current subscriber
location, subscriber mobile status on or off and many more, vlr is also
required in all technology 2g, 3g, 4g and 5g.
• The VLR contains a copy of most of the data stored at the HLR. It is,
however, temporary data which exists for only as long as the
subscriber is “active” in the particular area covered by the VLR.

44. Cont…..
• The VLR database will therefore contain some duplicate data as well
as more precise data relevant to the subscriber remaining within the
VLR coverage (here coverage means status of customer of last lac
location area code updation )
• The VLR provides a local database for the subscribers wherever they
are physically located within a PLMN, this may or may not be the
“home” system.
• This function eliminates the need for excessive and time-consuming
references to the “home” HLR database.

45. List of additional data stored in the VLR
• Location Area Identity (LAI).
• Temporary Mobile Subscriber Identity (TMSI).
• Mobile Station Roaming Number (MSRN).
• Mobile status (busy/free/no answer etc.).

46. Hierarchical location management
• Hierarchical location management in mobile computing refers to the method of
organizing and managing the location information of mobile users and devices in
a hierarchical structure. This approach helps in efficiently tracking, updating, and
retrieving the location data of mobile entities in a scalable manner. Here's a brief
overview of how it works and its key components:
• Key Concepts
• Hierarchy Levels: The hierarchical structure divides the geographical area into
multiple levels, such as cells, clusters of cells, and larger regions. Each level in the
hierarchy represents a different granularity of location information.
• Location Areas (LAs) and Registration Areas (RAs): Mobile networks are divided
into location areas or registration areas. Each area contains a set of base stations
or cells. Mobile devices report their locations when they move between these
areas.

47. Cont…..
• Location Registers: Different levels of location registers are used to
store location information. The two primary types are:
• Home Location Register (HLR): Stores permanent subscriber
information and the current location of the subscriber.
• Visitor Location Register (VLR): Temporarily stores information about
subscribers currently within the jurisdiction of a specific region.

48. Hierarchical Structure
• Cell Level: The smallest unit in the hierarchy, representing the
coverage area of a single base station.
• Cluster Level: Groups of adjacent cells form a cluster. Each cluster has
a cluster controller that manages the location information of all cells
within it.
• Region Level: Multiple clusters form a region. A region controller
oversees the clusters within the region.

49. Location Management Operations
• Location Update: When a mobile device moves from one area to another
(e.g., from one cell to another or from one cluster to another), it performs
a location update. This update is registered in the corresponding location
registers.
• Paging: When a call or data session is initiated for a mobile device, the
network uses the location information to page the device. Paging typically
starts at the highest level (region) and moves downwards in the hierarchy
to locate the device.
• Handoff Management: As a mobile device moves, the handoff process
ensures continuous connectivity by transferring the ongoing session from
one base station to another. Hierarchical location management helps
optimize this process by minimizing the signaling overhead.

50. Advantages
• Scalability: Hierarchical management scales well with the increasing
number of mobile users and devices.
• Efficiency: Reduces the signalling overhead by limiting location
updates and paging operations to the necessary hierarchy levels.
• Reduced Latency: Faster location retrieval and handoff processes due
to organized and structured location data.

51. Challenges
• Complexity: Managing a hierarchical structure adds complexity to the
network design and operation.
• Update Overhead: Frequent location updates can still lead to
significant signaling overhead, especially in highly dynamic
environments.
• Latency: Although reduced, latency can still be an issue if the
hierarchy is not well-optimized.

52. Handoffs
• Handoffs (or handovers) in mobile computing refer to the process of transferring an
active call or data session from one cell (base station) to another without disconnecting
the session. This is crucial for maintaining continuous service when a mobile device
moves across the coverage areas of different cells. Here are the key aspects of handoffs
in mobile computing:
• Types of Handoffs
• Hard Handoff: Also known as break-before-make, this type involves breaking the
connection with the current cell before establishing a new connection with the target
cell. It is typically used in systems like GSM (Global System for Mobile Communications).
• Advantages: Simpler implementation.
• Disadvantages: Brief interruption in service, potential for dropped calls.
• Soft Handoff: Also known as make-before-break, this type allows the mobile device to
maintain connections with multiple cells simultaneously before switching to the best cell.
It is used in CDMA (Code Division Multiple Access) systems.

53. Cont….
• Advantages: Reduced likelihood of dropped calls, smoother transition.
• Disadvantages: More complex and resource-intensive.
• Horizontal Handoff: Occurs between cells of the same network
technology (e.g., LTE to LTE).
• Advantages: Typically simpler and faster.
• Disadvantages: Limited to the same network technology.
• Vertical Handoff: Involves switching between different network
technologies (e.g., from Wi-Fi to LTE).
• Advantages: Flexibility to maintain connectivity across different networks.
• Disadvantages: More complex due to differing network protocols.

54. Handoff Process
• Measurement: The mobile device continuously measures signal
strength, quality, and other parameters of neighboring cells.
• Decision: Based on the measurements, the network or the mobile
device decides when a handoff is necessary. Factors considered
include signal strength, quality of service, and network load.
• Execution: The network coordinates the handoff by establishing a
new connection with the target cell and transferring the session
information. For hard handoffs, the old connection is released after
the new one is established.

55. policy based handoff process
• In cellular telecommunications, the terms handover or handoff refers
to the process of transferring an ongoing call or data connectivity
from one Base Station to another Base Station.
• When a mobile moves into a different cell while the conversation is in
progress then the MSC (Mobile Switching Center) transfers the call to
a new channel belonging to the new Base Station.

56. Cont…..
• When a mobile user A moves from one cell to another cell then BSC 1
signal strength loses for the mobile User A and the signal strength of
BSC 2 increases and thus ongoing calls or data connectivity for mobile
users goes on without interrupting.

57. channel allocation in cellular systems
• Channel Allocation means to allocate the available channels to the cells in a
cellular system. When a user wants to make a call request then by using
channel allocation strategies their requests are fulfilled. Channel Allocation
Strategies are designed in such a way that there is efficient use of
frequencies, time slots and bandwidth.
• Types of Channel Allocation Strategies:
• These are Fixed, Dynamic, Hybrid Channel Allocation and Borrowing
Channel Allocation as explained as following below.
• Fixed Channel Allocation (FCA):
• Fixed Channel Allocation is a strategy in which fixed number of channels or
voice channels are allocated to the cells. Once the channels are allocated
to the specific cells then they cannot be changed. In FCA channels are
allocated in a manner that maximize Frequency reuse.

59. Cont…..
• In cell A 20 Channels or Voice channels are allocated. If all channels
are occupied and user make a call then the call is blocked. Borrowing
Channels handles this type of problem. This cell borrow channels
from other cells.
• Advantages :
• Simple to implement and manage
• Does not require complex equipment or algorithms
• Disadvantages :
• Limited channel utilization as unused channels remain unused.
• Susceptible to interference and congestion.

60. Dynamic Channel Allocation (DCA):
• Dynamic Channel allocation is a strategy in which channels are not permanently
allocated to the cells. When a User makes a call request then Base Station (BS)
send that request to the Mobile Station Center (MSC) for the allocation of
channels or voice channels. This way the likelihood of blocking calls is reduced. As
traffic increases more channels are assigned and vice-versa.
• Advantages :
• Efficient use of available bandwidth.
• Reduces call blocking and improves call quality.
• Allows for dynamic allocation of resources.
• Disadvantages :
• Requires more complex equipment and algorithms.
• May result in call drops or poor quality if resources are not available

61. Hybrid Channel Allocation (HCA):
• Hybrid Channel Allocation is a combination of both Fixed Channel Allocation
(FCA) and Dynamic Channel Allocation (DCA). The total number of channels or
voice channels are divided into fixed and dynamic set. When a user make a call
then first fixed set of channels are utilized but if all the fixed sets are busy then
dynamic sets are used. The main purpose of HCA is to work efficiently under
heavy traffic and to maintain a minimum S/I.
• Advantages :
• Provides the benefits of both FCA and DCA.
• Allows for dynamic allocation of resources while maintaining predictable call
quality and reliability.
• Disadvantages :
• Requires more complex equipment and algorithms than FCA.
• May not provide the same level of efficiency as pure DCA.

62. Borrowing Channel Allocation (BCA):
• when a cell experiences high traffic demand and all of its channels are occupied, it can
borrow channels from neighboring cells that are not being used at that time. The
borrowed channels are assigned to the busy cell and are used to support the additional
traffic demand. Once the demand subsides, the borrowed channels are released and
returned to their home cell. BCA can be implemented manually or automatically using
algorithms or policies but the main disadvantage is that if the borrowed channel is
reclaimed by the original cell the call drop may occur.
• Advantages :
• Efficient use of available bandwidth.
• Reduces call blocking and improves call quality.
• Disadvantages :
• Increases interference between cells.
• Can cause call drops if borrowed channels are reclaimed by the home cell.

63. CDMA
• CDMA stands for Code Division Multiple Access.
• It is basically a channel access method and is also an example of
multiple access.
• Multiple access basically means that information by several
transmitters can be sent simultaneously onto a single communication
channel.

64. Cont……
• There are multiple users which are provided or assigned variant
CDMA codes and thus the users can access the entire band of
frequencies or the whole bandwidth.
• This method does not limit the frequency range of the user.
• Hence, with the help of CDMA, multiple users can share a band of
frequencies without any kind of undue interference between them.
• CDMA makes the use of spectrum technology along with analog to
digital conversion(ADC).
• It is thus used by various radio communication technologies. Mainly,
it is used for mobile communication.

65. Characteristics of CDMA
• It allows more users to connect at a given time and thus provides improved
data and voice communication capacity.
• A full spectrum is used by all the channels in CDMA.
• CDMA systems make the use of power control to eliminate the interference
and noise and to thus improve the network quality.
• CDMA encodes the user transmissions into distinct and unique codes in
order to secure its signals.
• In CDMA systems all the cells can thus use the same frequency.
• CDMA systems have a soft capacity.Thus there is no particular limit to the
number of users in a CDMA system but with increase in the number of
users the performance degrades.

66. CDMA

67. GPRS(General Packet Radio Service)
• GPRS is an expansion Global System for Mobile Communication.
• It is basically a packet-oriented mobile data standard on the 2G and
3G cellular communication network’s global system for mobile
communication.
• GPRS was built up by European Telecommunications Standards
Institute (ETSI) because of the prior CDPD, and I-mode packet
switched cell advances.

68. Cont……
• GPRS overrides the wired associations, as this framework has
streamlined access to the packet information’s network like the web.
• The packet radio standard is utilized by GPRS to transport client
information packets in a structured route between GSM versatile
stations and external packet information networks.
• These packets can be straightforwardly directed to the packet
changed systems from the GPRS portable stations.

69. Goals Of GPRS:
• Consistent IP services
• Leverage industry investment in IP
• Open Architecture
• Service innovation independent of infrastructure

70. Services Offered:
• SMS messaging and broadcasting
• Push-to-talk over cellular
• Instant messaging and presence
• Multimedia messaging service
• Point-to-Point and Point-to-Multipoint services
• Protocols supported:
• Internet Protocol (IP)
• Point-To-Point Protocol (PPP)

71. Benefits Of GPRS:
• Mobility:
The capacity to keep up consistent voice and information interchanges while
moving.
• Cost Efficient:
Communication via GPRS is cheaper than through the regular GSM network.
• Immediacy:
Allows customers to obtain connectivity when needed, regardless of location and
without a lengthy login session.
• Localization:
Enables customers to acquire data applicable to their present area.
• Easy Billing:
GPRS packet transmission offers an easier to use billing than that offered by
circuit switched administrations.

72. THANK YOU 