Cellular networks have evolved from 0G to 5G over several generations of technology. 1G networks in the early 1980s used analog transmission for primarily voice calls. 2G digital networks in the late 1980s enabled services like text messages. 3G networks in the 2000s supported broadband multimedia with speeds up to 2Mbps. 4G networks since 2010 provide faster "anytime, anywhere" services using IP. Research into 5G beyond 2020 aims for speeds over 10Gbps and connectivity of billions of devices. Each generation brought major improvements in speed and capabilities.
5G NR is a contradictory complex, and it is difficult to have both capacity and coverage. 5G expands the system capacity by expanding the bandwidth of the spectrum. The frequency range extends from below 3GHz in the 4G era to the millimeter wave band, and the single carrier bandwidth is increased from 20MHz to more than 100MHz. But the higher the frequency band, the smaller the coverage of the base station, and the operator has to build more base stations.
What are the Benefits of LoRaWAN Technology?
Today, we talk about the seven benefits of LoRaWAN technology application.
In December 2021, LoRaWAN officially became the ITU International Standard for Low Power Wide Area Networks and has been endorsed by the International Telecommunication Union (ITU).
LoRaWAN is developed as an open standard and has been widely recognized by the low power wide area network community. The rapid adoption of this standard for global IoT low-power wide-area networks is a testament to its universality.
LoRaWAN is now a very popular LPWA communication standard that uses unlicensed radio spectrum in the ISM (Industrial, Scientific, Medical) band at frequencies ranging from approximately 433 MHz to 868 MHz, 915 MHz (standards vary around the world).
In the IoT connectivity environment, in addition to smart home networking and office space scenarios, many IoT devices will be connected and communicated in remote environments where the new environment will be inaccessible and require power connections due to M2M transmission coverage limitations.
This article introduces the design of the antenna and recommends two tested low-cost PCB antennas. These PCB antennas can be used with Bluetooth Low Energy (BLE) solutions. For the best performance, BLE and BLE 2.4GHz radio frequencies must be correctly matched to their antennas.
The Next Generation Mobile Networks Alliance feels that 5G should be rolled out by 2020 to meet business and consumer demands. In addition to providing simply faster speeds, they predict that 5G networks also will need to meet new use cases such as the Internet of Things (internet connected devices) as well as broadcast-like services and lifeline communication in times of natural disaster. Although updated standards that define capabilities beyond those defined in the current 4G standards are under consideration, those new capabilities have been grouped under the current ITU-T 4G standards. The U.S. Federal Communications Commission (FCC) approved the spectrum for 5G, including the 28 Gigahertz, 37 GHz and 39 GHz bands, on July 14, 2016. 5G research and development also aims at improved support of machine to machine communication, also known as the Internet of things, aiming at lower cost, lower battery consumption and lower latency than 4G equipment. To put it simply, the use cases for 4G networks has expanded well beyond the initial scope of the standard. 5G is what you get when you reset the standard/design to cope with the increase in scope.4G networks don’t just support mobile devices anymore. IOT (Internet of Things) devices are everywhere and the number of them is only going to increase. We’re seeing 4G modems in smart watches, in CCTVs and even in doorbells.
After the analysis of LoRa vs ZigBee technologies, you will learn about what is the difference between LoRa and ZigBee technology.
In LoRa vs ZigBee technology, LoRa is a variety of wireless technologies for IoT applications, which can form a local area network or wide area network.
In LoRa vs ZigBee technology, ZigBee is a low-power local area network protocol based on IEEE802.15.4 standard.
In LoRa vs ZigBee technology, LoRa technology has the characteristics of long-range, low power consumption (long battery life), multi-node, and low cost.
In LoRa vs ZigBee technology, ZigBee technology has the characteristics of close range, low complexity, low power consumption, low rate, and low cost.
5G NR is a contradictory complex, and it is difficult to have both capacity and coverage. 5G expands the system capacity by expanding the bandwidth of the spectrum. The frequency range extends from below 3GHz in the 4G era to the millimeter wave band, and the single carrier bandwidth is increased from 20MHz to more than 100MHz. But the higher the frequency band, the smaller the coverage of the base station, and the operator has to build more base stations.
What are the Benefits of LoRaWAN Technology?
Today, we talk about the seven benefits of LoRaWAN technology application.
In December 2021, LoRaWAN officially became the ITU International Standard for Low Power Wide Area Networks and has been endorsed by the International Telecommunication Union (ITU).
LoRaWAN is developed as an open standard and has been widely recognized by the low power wide area network community. The rapid adoption of this standard for global IoT low-power wide-area networks is a testament to its universality.
LoRaWAN is now a very popular LPWA communication standard that uses unlicensed radio spectrum in the ISM (Industrial, Scientific, Medical) band at frequencies ranging from approximately 433 MHz to 868 MHz, 915 MHz (standards vary around the world).
In the IoT connectivity environment, in addition to smart home networking and office space scenarios, many IoT devices will be connected and communicated in remote environments where the new environment will be inaccessible and require power connections due to M2M transmission coverage limitations.
This article introduces the design of the antenna and recommends two tested low-cost PCB antennas. These PCB antennas can be used with Bluetooth Low Energy (BLE) solutions. For the best performance, BLE and BLE 2.4GHz radio frequencies must be correctly matched to their antennas.
The Next Generation Mobile Networks Alliance feels that 5G should be rolled out by 2020 to meet business and consumer demands. In addition to providing simply faster speeds, they predict that 5G networks also will need to meet new use cases such as the Internet of Things (internet connected devices) as well as broadcast-like services and lifeline communication in times of natural disaster. Although updated standards that define capabilities beyond those defined in the current 4G standards are under consideration, those new capabilities have been grouped under the current ITU-T 4G standards. The U.S. Federal Communications Commission (FCC) approved the spectrum for 5G, including the 28 Gigahertz, 37 GHz and 39 GHz bands, on July 14, 2016. 5G research and development also aims at improved support of machine to machine communication, also known as the Internet of things, aiming at lower cost, lower battery consumption and lower latency than 4G equipment. To put it simply, the use cases for 4G networks has expanded well beyond the initial scope of the standard. 5G is what you get when you reset the standard/design to cope with the increase in scope.4G networks don’t just support mobile devices anymore. IOT (Internet of Things) devices are everywhere and the number of them is only going to increase. We’re seeing 4G modems in smart watches, in CCTVs and even in doorbells.
After the analysis of LoRa vs ZigBee technologies, you will learn about what is the difference between LoRa and ZigBee technology.
In LoRa vs ZigBee technology, LoRa is a variety of wireless technologies for IoT applications, which can form a local area network or wide area network.
In LoRa vs ZigBee technology, ZigBee is a low-power local area network protocol based on IEEE802.15.4 standard.
In LoRa vs ZigBee technology, LoRa technology has the characteristics of long-range, low power consumption (long battery life), multi-node, and low cost.
In LoRa vs ZigBee technology, ZigBee technology has the characteristics of close range, low complexity, low power consumption, low rate, and low cost.
MIMO 2.4Ghz 300Mbps system &P Wi Max Wisp Wi Fi Wi Max Mesh Systems 2010...Hotware International Inc.
Hotware builds long-range wireless solutions for data, voice and TV. With a decade of experience and development in the long-rang cordless phone industry, Hotware International is a specialist in long-range wireless communication solutions and applications.
Hotware Total Solution Division completed its full offering and was released in 2008 and presently have several National ISP development projects under deployment through the world , These include ISP WiFi with roaming, VOIP and IPTV delivery with on site training and project management support.
MIMO 2.4Ghz 300Mbps system &P Wi Max Wisp Wi Fi Wi Max Mesh Systems 2010...Hotware International Inc.
Hotware builds long-range wireless solutions for data, voice and TV. With a decade of experience and development in the long-rang cordless phone industry, Hotware International is a specialist in long-range wireless communication solutions and applications.
Hotware Total Solution Division completed its full offering and was released in 2008 and presently have several National ISP development projects under deployment through the world , These include ISP WiFi with roaming, VOIP and IPTV delivery with on site training and project management support.
Final project report on grocery store management system..pdfKamal Acharya
In today’s fast-changing business environment, it’s extremely important to be able to respond to client needs in the most effective and timely manner. If your customers wish to see your business online and have instant access to your products or services.
Online Grocery Store is an e-commerce website, which retails various grocery products. This project allows viewing various products available enables registered users to purchase desired products instantly using Paytm, UPI payment processor (Instant Pay) and also can place order by using Cash on Delivery (Pay Later) option. This project provides an easy access to Administrators and Managers to view orders placed using Pay Later and Instant Pay options.
In order to develop an e-commerce website, a number of Technologies must be studied and understood. These include multi-tiered architecture, server and client-side scripting techniques, implementation technologies, programming language (such as PHP, HTML, CSS, JavaScript) and MySQL relational databases. This is a project with the objective to develop a basic website where a consumer is provided with a shopping cart website and also to know about the technologies used to develop such a website.
This document will discuss each of the underlying technologies to create and implement an e- commerce website.
Automobile Management System Project Report.pdfKamal Acharya
The proposed project is developed to manage the automobile in the automobile dealer company. The main module in this project is login, automobile management, customer management, sales, complaints and reports. The first module is the login. The automobile showroom owner should login to the project for usage. The username and password are verified and if it is correct, next form opens. If the username and password are not correct, it shows the error message.
When a customer search for a automobile, if the automobile is available, they will be taken to a page that shows the details of the automobile including automobile name, automobile ID, quantity, price etc. “Automobile Management System” is useful for maintaining automobiles, customers effectively and hence helps for establishing good relation between customer and automobile organization. It contains various customized modules for effectively maintaining automobiles and stock information accurately and safely.
When the automobile is sold to the customer, stock will be reduced automatically. When a new purchase is made, stock will be increased automatically. While selecting automobiles for sale, the proposed software will automatically check for total number of available stock of that particular item, if the total stock of that particular item is less than 5, software will notify the user to purchase the particular item.
Also when the user tries to sale items which are not in stock, the system will prompt the user that the stock is not enough. Customers of this system can search for a automobile; can purchase a automobile easily by selecting fast. On the other hand the stock of automobiles can be maintained perfectly by the automobile shop manager overcoming the drawbacks of existing system.
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)MdTanvirMahtab2
This presentation is about the working procedure of Shahjalal Fertilizer Company Limited (SFCL). A Govt. owned Company of Bangladesh Chemical Industries Corporation under Ministry of Industries.
Student information management system project report ii.pdfKamal Acharya
Our project explains about the student management. This project mainly explains the various actions related to student details. This project shows some ease in adding, editing and deleting the student details. It also provides a less time consuming process for viewing, adding, editing and deleting the marks of the students.
Explore the innovative world of trenchless pipe repair with our comprehensive guide, "The Benefits and Techniques of Trenchless Pipe Repair." This document delves into the modern methods of repairing underground pipes without the need for extensive excavation, highlighting the numerous advantages and the latest techniques used in the industry.
Learn about the cost savings, reduced environmental impact, and minimal disruption associated with trenchless technology. Discover detailed explanations of popular techniques such as pipe bursting, cured-in-place pipe (CIPP) lining, and directional drilling. Understand how these methods can be applied to various types of infrastructure, from residential plumbing to large-scale municipal systems.
Ideal for homeowners, contractors, engineers, and anyone interested in modern plumbing solutions, this guide provides valuable insights into why trenchless pipe repair is becoming the preferred choice for pipe rehabilitation. Stay informed about the latest advancements and best practices in the field.
Immunizing Image Classifiers Against Localized Adversary Attacksgerogepatton
This paper addresses the vulnerability of deep learning models, particularly convolutional neural networks
(CNN)s, to adversarial attacks and presents a proactive training technique designed to counter them. We
introduce a novel volumization algorithm, which transforms 2D images into 3D volumetric representations.
When combined with 3D convolution and deep curriculum learning optimization (CLO), itsignificantly improves
the immunity of models against localized universal attacks by up to 40%. We evaluate our proposed approach
using contemporary CNN architectures and the modified Canadian Institute for Advanced Research (CIFAR-10
and CIFAR-100) and ImageNet Large Scale Visual Recognition Challenge (ILSVRC12) datasets, showcasing
accuracy improvements over previous techniques. The results indicate that the combination of the volumetric
input and curriculum learning holds significant promise for mitigating adversarial attacks without necessitating
adversary training.
Event Management System Vb Net Project Report.pdfKamal Acharya
In present era, the scopes of information technology growing with a very fast .We do not see any are untouched from this industry. The scope of information technology has become wider includes: Business and industry. Household Business, Communication, Education, Entertainment, Science, Medicine, Engineering, Distance Learning, Weather Forecasting. Carrier Searching and so on.
My project named “Event Management System” is software that store and maintained all events coordinated in college. It also helpful to print related reports. My project will help to record the events coordinated by faculties with their Name, Event subject, date & details in an efficient & effective ways.
In my system we have to make a system by which a user can record all events coordinated by a particular faculty. In our proposed system some more featured are added which differs it from the existing system such as security.
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2. cience and technology of communication over a distance.
he ability to convey information quickly accurately and efficiency
as been one of the main focuses driving human innovation.
Telecommunication:
Cellular network:
Base stations transmit to and receive from mobiles at the
assigned spectrum
Multiple base stations use the same spectrum (spectral reuse)
The service area of each base station is called a cell
Each mobile terminal is typically served by the ‘closest’ base
stations
Wireless:
Term used to describe any computer network where there
Is no physical wired connection between sender and receiver.
3. CELLULAR NETWORKS: FROM 0G
TO 5G
0G: Briefcase-size mobile radio telephones
1G: First generation wireless cellular: Early 1980s
Analog transmission, primarily speech: AMPS (Advanced Mobile Phone
Systems) and others
2G: Second generation wireless cellular: Late 1980s
Digital transmission
Primarily speech and low bit-rate data (9.6 Kbps)
High-tier: GSM, IS-95 (CDMA), etc
Low-tier (PCS): Low-cost, low-power, low-mobility e.g. PACS
2.5G: 2G evolved to medium rate (< 100kbps) data
3G: future Broadband multimedia
144 kbps - 384 kbps for high-mobility, high coverage
2 Mbps for low-mobility and low coverage
4G: IP-based “anytime, anywhere” voice, data, and
multimedia telephony at faster data rates than 3G
Beyond 4G: research in 5G
Overview:
4. Mobile radio telephones were used for military communications
in early 20th century
Car-based telephones first introduced in mid 1940s
Single large transmitter on top of a tall building
Single channel used for sending and receiving
To talk, user pushed a button, enabled transmission and disabled
reception
Became known as “push-to-talk” in 1950s
CB-radio, taxis, police cars use this technology
IMTS (Improved Mobile Telephone System) introduced in 1960s
Used two channels (one for sending, one for receiving)
No need for push-to-talk
Used 23 channels from 150 MHz to 450 MHz
0G TECHNOLOGY
5. 1G TECHNOLOGY
Advanced Mobile Phone Service (AMPS) invented at Bell
Labs and first installed in 1982
Its speed was up to 2.4kbps
It use analog signal
It allows the voice calls in 1 country.
Drawbacks:
Poor voice quality
Large phone size
Limited capacity
poor battery life
Poor handoff reliability
6. SECURITY ISSUES WITH 1G
Analog cellular phones are insecure
Anyone with an all band radio receiver can
listen in (many scandals)
Theft of airtime:
all band radio receiver connected to a computer
can record 32 bit serial number and phone number of
subscribers when calling
can collect a large database by driving around
Thieves go into business - reprogram stolen phones and
resell them
7. Based on digital transmission means convert analog to
digital.
Based on GSM(Global system for mobile communication)
Launched in 1991
Sped up to 64kbps.
2G TECHNOLOGY
Features include:
Enables services such as text messages, pic messages and MMS
Provides better quality and capacity.
Drawbacks:
These system are unable to handle complex data such as video
2G requires digital signal to help mobile phone work.
8. GSM (GLOBAL SYSTEM FOR MOBILE
COMMUNICATIONS)
Completely designed from scratch (no backward
compatibility)
Uses 124 channels per cell, each channel can support 8
users through TDM (992 users max)
Some channels used for control signals, etc
Several flavors based on frequency:
GSM (900 MHz)
GSM 1800 (called DCS 1800)
GSM 1900 (called DCS 1900) - used in North America
GSM 1900 phone only works in North America.
In Europe, you can transfer your SIM (Subscriber
Identity Module) card to a phone of the correct frequency.
This is called SIM-roaming.
9. GSM (2G-TDMA)
Circuit mode data
Transparent mode
Non-transparent mode using radio link protocol
Data rate up to 9.6kb/s
Short message service
Limited to 160 characters
Packet mode data: Plans for GSM Phase 2+
Architecture specification very detailed (500 pages)
Defines several interfaces for multiple suppliers
10. Its between 2G and 3G of mobile communication.
2G cellular technology combined with GPRS
(general packet radio service).
GPRS -Launched in 1997
It offers 110kbps.
2.75G technology
2.5G technology:
Replace GPRS by EDGE
EDGE-introduced in 2003.
(Enhanced Data rates for GSM Evolution)
All are see E symbol in above SIM representation
It offers 170kbps.
11. IS-95
It is alternative of 2G technology.
Developed by QUALCOMM.
It offers 14kbps.
After improvement of cellular service in large-scale of
2G technology changed into GPRS.
GPRS is used in 2.5G that already known.
Simple word in 2G called =GSM+
GPRS+
EDGE
12. 3G TECHNOLOGY(WCDMA)
ITU introduce 3G specification with IMT-2000
EDGE technology also joined in this technology
but not for long time.
It offers 144kbps to 2mbps.
It increased its bandwidth and data transfer rates.
Features include:
Faster communication.
Video calling.
3D gamming
TV streaming/phone calls/mobile TV
11 sec-1.5min. Time to download a 3min mp3 song.
13. CDMA 200
Alternative of 3G technology
It offers 153kbps
EV-DO next version of CDMA
EV-DO
REV-O REV-A REV-B
Offers 2.4mbps Offers 3.1mbps 10mbps
UMTS-offers only 384kps
Next version of UMTS is HSDPA
HSDPA-offers up to 21mbps
Alternative of EV-DO
14. 3.5G TECHNOLOGY
High Speed Packet Access (HSPA) is an amalgamation of
two mobile telephony protocols, High Speed Downlink
Packet Access (HSDPA) and High Speed Uplink Packet
Access (HSUPA), that extends and improves the performance
of existing WCDMA protocols
3.5G introduces many new features that will enhance the
UMTS technology in future. 1xEV-DV already supports most
of the features that will be provided in 3.5G. These include:
- Adaptive Modulation and Coding
- Fast Scheduling
- Backward compatibility with 3G
- Enhanced Air Interface
15. 4G TECHNOLOGY(LTE)
LTE stands for Long Term Evolution
Next Generation mobile broadband
technology
Promises data transfer rates of 100
Mbps
Based on UMTS 3G technology
Optimized for All-IP traffic
16. 5G TECHNOLOGY
5G is the short for fifth generation, a mobile
broadband technology that is in the early
stages of works and likely to be in place six to
seven years from now.
A 5G network will be able to handle 10,000
times more call and data traffic than the
current 3G or 4G network.
Data download speeds on 5G networks are
likely to be several hundred times more than
4G.
5G mobile technology will change the
means to use cell phones within very high
bandwidth.
17. BRIEF IDEA ABOUT 5G
CURRENT STATUS OF 5G?
The European Telecommunications Standards Institute is
formulating 5G global technology standards, which are likely to
be formalized by 2019.
Telecom companies such as Nokia, Ericsson, NTT DoCoMo,
Samsung, Huawei and Fujitsu are driving bulk of the 5G-
related innovations.
PEOPLE WILL BE ABLE TO EXPERIENCE WITH 5G.
5G networks are likely to be rolled out commercially
between 2020 and 2025. If the global standards are finalized by
2019, the earliest commercial deployments could happen by
2020.
3G AND 4G HANDSETS DOESN’T RUN ON 5G
NETWORKS.
No. 5G will require new chipsets and devices capable
of supporting speeds upwards of 10 gigabits per second. 4G and
3G run at a fraction of that speed.
18. It is the next major phase of mobile
telecommunication & wireless system.
It is 10 times more faster than 4G.
It has a expected speed of 1gbps.
Lower cost than the previous version.
It is expected to come around the year 2017
5G CONT….
20. E
A
DF
G C
B
E
A
DF
G C
B
E
A
DF
G C
B
Cell Design
•Cells grouped into a cluster of seven
•Letters indicate frequency use
•For each frequency, a buffer of two cells is used before reuse
•To add more users, smaller cells (microcells) are used
•Frequencies may not need to be different in CDMA (soft handoff)
21. CELLULAR NETWORK
ORGANIZATION
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 (churches,
high rise buildings) -
Operators pay around $500 per month for BS
10 to 50 frequencies assigned to each cell
Cells set up such that antennas of all neighbors are
equidistant (hexagonal pattern)
In North America, two 25-MHz bands allocated
to AMPS
One for transmission from base to mobile unit
One for transmission from mobile unit to base
22. APPROACHES TO INCREASE
CAPACITY
Adding/reassigning channels - some channels are not
used
Frequency borrowing – frequencies are taken from
adjacent cells by congested cells
Cell splitting – cells in areas of high usage can be
split into smaller cells
Microcells – antennas move to buildings, hills, and
lamp posts
23.
24.
25.
26. DIFFERENCES BETWEEN FIRST
AND SECOND GENERATION
SYSTEMS
Digital traffic channels – first-generation
systems are almost purely analog; second-
generation systems are digital
Encryption – all second generation
systems provide encryption to prevent
eavesdropping
Error detection and correction – second-
generation digital traffic allows for
detection and correction, giving clear voice
reception
Channel access – second-generation
systems allow channels to be dynamically
shared by a number of users
27. INTEGRATING DATA OVER
CELLULAR
Direct access to digital channel
Voice and data using one handset
PCS 1900 (GSM-1900)
9.6 kbps circuit switched data
14.4 kbps under definition
Packet mode specified
Short message service
IS-95-based CDMA
13 kbps circuit switched data
Packet mode specified
Short message service
28.
29.
30.
31.
32.
33.
34. MOBILE STATION AND BASE STATION
SUBSYSTEM (BSS)Mobile station
Mobile station communicates across Um interface (air
interface) with base station transceiver in same cell as mobile
unit
Mobile equipment (ME) – physical terminal, such as a
telephone or PCS
ME includes radio transceiver, digital signal processors and
subscriber identity module (SIM)
GSM subscriber units are generic until SIM is inserted
SIMs roam, not necessarily the subscriber devices
BSS
BSS consists of base station controller and one or more base
transceiver stations (BTS)
BSC reserves radio frequencies, manages handoff of mobile
unit from one cell to another within BSS, and controls paging
35. NETWORK SUBSYSTEM CENTERMobile Switching Center (MSC) is at core; consists of
several databases
Home location register (HLR) database – stores
information about each subscriber that belongs to it
Visitor location register (VLR) database –
maintains information about subscribers currently
physically in the region
Authentication center database (AuC) – used for
authentication activities, holds encryption keys
Equipment identity register database (EIR) – keeps
track of the type of equipment that exists at the
mobile station
36. GSM LOCATION SERVICES
Public
Switched
Telephone
Network
(PSTN)
Gateway
MTSC
VLR HLR
Terminating
MSC 1
1. Call made to mobile unit (cellular phone)
2. Telephone network recognizes number
and gives to gateway MSC
3. MSC can’t route further, interrogates
user’s HLR
4. Interrogates VLR currently serving user
(roaming number request)
5. Routing number returned to HLR and
then to gateway MSC
2
3
4
5
5
6
6. Call routed to terminating MSC
7. MSC asks VLR to correlate call to
the subscriber
8. VLR complies
9. Mobile unit is paged
10. Mobile unit responds, MSCs convey
information back to telephone
7 8
9
BTS
9 10
10
10 10
10
Legend: MTSC= Mobile Telephone Service Center, BTS = Base Transceiver Station
HLR=Home Location Register, VLR=Visiting Location Register
37. GSM PROTOCOL ARCHITECTURE
BSSMAP = BSS Mobile Application part
BTSM = BTS management
CM = Connection Management
LAPD = Link Access Protocol, D Channel
Base Transceiver
Station
Mobile
Station
Radio
LAPDm
RRM
Radio
LAPDm
RRM
MM
CM
64 Kbps
LAPD
BTSM
64 Kbps
MTP
SCCP
Base Station
Controller
64 Kbps
LAPD
BTSM
BSSMAP
64Kbps
MTP
SCCP
MM
CM
BSSMAP
Mobile Service
Switching Center
MM = Mobility Management
MTP = Message Transfer Part
RRM = Radio Resources Management
SCCP = Signal Connection Control Point
38. FUNCTIONS PROVIDED BY
PROTOCOLS
Protocols above the link layer of the GSM signaling
protocol architecture provide specific functions:
Radio resource management: controls setup,
termination and handoffs of radio channels
Mobility management: location and security (MTSO)
Connection management: connects end users
Mobile application part (MAP): between HLR,VLR
BTS management: management base system
39. 2G CDMA CELLULAR
IS-95 is the best known example of 2G with CDMA
Advantages of CDMA for Cellular
Frequency diversity – frequency-dependent
transmission impairments have less effect on
signal
Multipath resistance – chipping codes used for
CDMA exhibit low cross correlation and low
autocorrelation
Privacy – privacy is inherent since spread
spectrum is obtained by use of noise-like
signals
Graceful degradation – system only gradually
degrades as more users access the system
40. DRAWBACKS OF CDMA CELLULAR
Self-jamming – arriving transmissions from
multiple users not aligned on chip
boundaries unless users are perfectly
synchronized
Near-far problem – signals closer to the
receiver are received with less attenuation
than signals farther away
Soft handoff – requires that the mobile
acquires the new cell before it relinquishes
the old; this is more complex than hard
handoff used in FDMA and TDMA schemes
41. TYPES OF CHANNELS SUPPORTED
BY FORWARD LINK
Pilot (channel 0) - allows the mobile unit
to acquire timing information, provides
phase reference and provides means for
signal strength comparison
Synchronization (channel 32) - used by
mobile station to obtain identification
information about cellular system
Paging (channels 1 to 7) - contain
messages for one or more mobile stations
Traffic (channels 8 to 31 and 33 to 63) –
the forward channel supports 55 traffic
channels
42. FORWARD TRAFFIC CHANNEL
PROCESSING STEPS Speech is encoded at a rate of 8550 bps
Additional bits added for error detection
Data transmitted in 2-ms blocks with forward error
correction provided by a convolutional encoder
Data interleaved in blocks to reduce effects of errors
Data bits are scrambled, serving as a privacy mask
Power control information inserted into traffic channel
DS-SS function spreads the 19.2 kbps to a rate of 1.2288
Mbps using one row of 64 x 64 Walsh matrix
Digital bit stream modulated onto the carrier using
QPSK modulation scheme
47. ALTERNATIVES TO 3G CELLULAR
Major technical undertaking with many
organizational and marketing overtones.
Questions about the need for the additional
investment for 3G (happy with 2.5G)
Wireless LAN in public places such as shopping
malls and airports offer options
Other high-speed wireless-data solutions
compete with 3G
Mobitex low data rates (nominally 8 Kbps), it uses a narrowband
(2.5KHz) as compared to 30 KHz (GSM) and 5 MHz (3G).
Ricochet: 40 -128 kbps data rates. Bankruptcy
Flash-OFDM: 1.5 Mbps (upto 3 Mbps)
48. MAJOR MOBILE RADIO
STANDARDS
USA
Standard Type Year
Intro
Multiple
Access
Frequency
Band
(MHz)
Modulation Channe
l
BW
(KHz)
AMPS Cellular 1983 FDMA 824-894 FM 30
USDC Cellular 1991 TDMA 824-894 DQPSK 30
CDPD Cellular 1993 FH/Packet 824-894 GMSK 30
IS-95 Cellular/PCS 1993 CDMA 824-894
1800-2000
QPSK/BPSK 1250
FLEX Paging 1993 Simplex Several 4-FSK 15
DCS-1900
(GSM)
PCS 1994 TDMA 1850-1990 GMSK 200
PACS Cordless/PC
S
1994 TDMA/FDMA 1850-1990 DQPSK 300
49. MAJOR MOBILE RADIO
STANDARDS - EUROPE
Standard Type Year
Intro
Multiple
Access
Frequency
Band
(MHz)
Modulation Channe
l
BW
(KHz)
ETACS Cellular 1985 FDMA 900 FM 25
NMT-900 Cellular 1986 FDMA 890-960 FM 12.5
GSM Cellular/PCS 1990 TDMA 890-960 GMSK 200KHz
C-450 Cellular 1985 FDMA 450-465 FM 20-10
ERMES Paging 1993 FDMA4 Several 4-FSK 25
CT2 Cordless 1989 FDMA 864-868 GFSK 100
DECT Cordless 1993 TDMA 1880-1900 GFSK 1728
DCS-1800 Cordless/PC
S
1993 TDMA 1710-1880 GMSK 200
51. 4G SYSTEMS
Wireless networks with cellular data rates of 20
Mbits/second and beyond.
AT&T has began a two-phase upgrade of its wireless
network on the way to 4G Access.
Nortel developing developing features for Internet
protocol-based 4G networks
Alcatel, Ericsson, Nokia and Siemens found a new
Wireless World Research Forum (WWRF) for research
on wireless communications beyond 3G.
Many new technologies and techniques (multiplexing,
intelligent antennas, digital signal processing)
Industry response is mixed (some very critical)
52. ENGINEERING ISSUES
Steps in MTSO controlled call
TDMA design
CDMA design
Handoff
Power control
Traffic engineering
53. STEPS IN AN MTSO CONTROLLED
CALL BETWEEN MOBILE USERS
Mobile unit initialization
Mobile-originated call
Paging
Call accepted
Ongoing call
Handoff
Call blocking
Call termination
Call drop
Calls to/from fixed and remote mobile subscriber
54. MOBILE WIRELESS TDMA DESIGN
CONSIDERATIONS
Number of logical channels (number of
time slots in TDMA frame): 8
Maximum cell radius (R): 35 km
Frequency: region around 900 MHz
Maximum vehicle speed (Vm):250 km/hr
Maximum coding delay: approx. 20 ms
Maximum delay spread (∆m): 10 µs
Bandwidth: Not to exceed 200 kHz (25
kHz per channel)
55. MOBILE WIRELESS CDMA DESIGN
CONSIDERATIONS
Soft Handoff – mobile station temporarily
connected to more than one base station
simultaneously
RAKE receiver – when multiple versions
of a signal arrive more than one chip
interval apart, RAKE receiver attempts to
recover signals from multiple paths and
combine them
This method achieves better performance than
simply recovering dominant signal and
treating remaining signals as noise
56. WHAT IS WIMAX?
Worldwide Interoperability for Microwave
Access
Last mile wireless broadband access
Alternative to cable and DSL
Deliver data, voice, video
Support hundreds to thousands of
homes/business
57. Defined by IEEE as 802.16
Typical target environment:
Targets fixed, portable, and mobile stations
Environments with and without line of sight
Cell radius of 3-10 kilometers
Capacities of up to 40 Mbps per channel
Mobile network deployments of up to 15 Mbps, 3
km radius
58. BUILDS ON AND
EXTENDS WIFI TECHNOLOGY
Advantages of WiFi are:
Easy to deploy, unlicensed spectrum, low
cost
Supports (limited) mobility
But WiMax needs to address the following:
59. WIFI LIMITATIONS
Susceptible to interference
802.11 targets short-range indoor operation
(mostly)
Security is a concern
Limited level of mobility
WiMax is intended to complement WiFi
WiMax Forum: promotes WiMax and looks
after interoperability
61. ADVANTAGES OF DIGITAL
COMMUNICATIONS FOR
WIRELESS
Voice, data and fax can be integrated into a
single system
Better compression can lead to better channel
utilization
Error correction codes can be used for better
quality
Sophisticated encryption can be used