Transcript wireless _bb

ARIF KAN.G
CISCO N/W
ASSOCIATE
Broadband Wireless Access
Technologies
• Wireless Access Technologies
– Fixed Broadband Wireless Access
(LMDS/MMDS)
– Wireless Local Area Network (WLAN / WiFi)
(IEEE 802.11)
– Wireless Metropolitan Area Network (WMAN
/ WiMax) (IEEE 802.16)
– Cellular Mobile Telephony (GSMGPRS,EDGE / CDMA 2000 1x EVDO,EVDD)
(3G-UMTS/WCDMA)
2
LOCAL MULTIPOINT DISTRIBUTION SYSTEM
(LMDS)
3
LOCAL MULTIPOINT DISTRIBUTION SYSTEM
A new radio based access technology with
cellular architecture.
LMDS offers flexible high capacity connections
to private users and organizations.
LMDS can replace existing phone line cable and
other infrastructure.
LMDS can support services such as voice, data
video and internet from different platforms like
PSTN and ATM.
LMDS can be deployed for providing leased line
connectivity to individuals and corporate houses.
4
Local Multipoint Distribution
System





Broadband wireless technology operating in
the 28-GHz and 31-GHz ranges
Voice, data and video
Data rate in the range of 100s of Mbps
Available 2001?
Line-of-sight technology
5
LMDS Network
7
LMDS Applications
Central Office
Video
PSTN
Internet
Content &
Application
Providers
Backhaul for
Hotspots
Data,PSTN
Video Access
LMDS Cell Site
Data,PSTN
Video8Access
LMDS Cells
LMDS systems is composed
Of cells.
To CO
LMDS Cell Site
9
Factors Determining LMDS Cell
Size
Line-of-sight—LMDS requires direct line


Tall buildings may obstruct line of sight
Solution is to divide area into smaller cells
Antenna
height—placed
on
taller
buildings can serve larger cells without
obstructions
10
LMDS Signal Obstruction
No Signal
To CO
Shadow
Zone
LMDS Cell Site
Tall Building
Obstructs Signal
11
Divide LMDS Cells into Smaller
Cells
To CO
LMDS Cell Site
LMDS Cell12
Site
LMDS Antenna Height
To CO
13
NETWORK ARCHITECTURE OF
LMDS
1. Network Operations Centre (NOC)
2. Fiber based infrastructure
3. Central station
4. Customer Premises Equipment
14
Network Operations Centre (NOC)
• Contains NMS
• NMS controls a number of CSs & RSs
• NMS can configure maintain and
monitor both CS & RS
15
2.Fiber based infrastructure
• Interconnects the network node and the CS
• It consists of STM4/STM1 links
16
3. Central station
Sub divided into two units
i)Central Controller Station (CCS)
ii)Central Radio Station (CRS)
17
3 i) Central Controller Station (CCS)
Provides the interface to Network node
It can be connected to different networks
such as PSTN/ATM/IP
It has interfaces to accommodate
STM1/STM4,34Mbps,V5.2, for
establishing connections to different
networks.
18
ii)Central Radio Station (CRS)
Microwave transmission and reception
equipments.
The height of the antenna should be such that
it can provide LOS for the remote stations of
targeted area
It uses sectored antennae for broadcasting
towards remote stations with coverage range
varying from 3 to 10 km depending up on the
frequencies used.
19
LMDS Hub and Remote Unit
LMDS Hub Unit
LMDS Remote Unit
20
REMOTE TERMINAL STATION
CONTAINS
1.Roof Top unit
2.Network Interface Unit
3.Customer Premises Equipment
21
22
Roof Top Unit
It uses a directional antenna to establish a M/W
link with the Central station
NIU connects the RTU to CPE.
NIU provides the gateway between RF
components and in building appliances
NIUs are available in scalable and non scalable
forms depending upon customer requirements.
23
Scalable(configurable)NIU
•A scalable NIU is flexible and fully
configurable.
•It can support two way digital wireless
voice,data and video communication for
commercial and business use.
•NIU is configured by the NOC at the CS.
•NIUs of this type allows N/W operators to
meet customer’s requirement efficiently.
•Costly and is suitable for higher end users
24
Non scalable NIU.
•Not configurable.Provides a fixed
combination of interfaces
•Cost effective and suitable for medium
sized business and home segments.
25
FREQUENCY BANDS
LMDS services are available in
3.5GHz,10.5GHz,26GHz and 28GHz.
Frequency
Coverage
3.5GHz (3.4-3.6)
10-15km
10.5
(10.15-10.65)
8-10km
26
(24.5-26.5)
3-5km
28
(27.5-29.5)
3-5km
26
•The data rate and coverage depends on frequency
used and the Geo climatic factors.
•At frequencies above 10GHz rain attenuation is
predominant.
•The higher frequency bands are suitable for high
density high bit rate users in small area.
•Low frequency LMDS can cover a large area
containing scattered low data users.
•BSNL plans to procure the systems in 10.5GHz and
26 GHz frequency bands on primary basis.
27
Capacity
•The bandwidth of the radio channel used will
normally be 28MHz.
•The system is normally configured with four sectors
in a cell and one carrier per sector.
•The number of sectors can be increased or decreased
depending upon the traffic.
•The traffic carrying capacity in Mbps depends on the
modulation technique employed in the equipment
which is vendor dependent,
28
Benefits of LMDS
• lower deployment costs
• ease and speed of deployment
– systems can be deployed rapidly with minimal disruption
to the community and the environment
• fast realization of revenue
• demand-based build out
– services and coverage areas can be easily
expanded as customer demand warrants
• cost-effective network maintenance,
management, and operating costs
29
Disadvantages of LMDS
Disadvantages


Requires line-of-sight between buildings;
LMDS network is limited by surrounding
objects
Affected by precipitation; LMDS systems
are susceptible to interference from rain
and fog
30
MULTICHANNEL MUTIPOINT
DISTRIBUTION SYSTEM (MMDS)
31
Multichannel Multipoint
Distribution System
Similar to LMDS, MMDS can transmit video,
voice, or data signals at 1.5 Mbps downstream
and 300 Kbps upstream at distances up to 35
miles
32
MMDS Layout
By using lower frequencies, MMDS signals travel longer
distances and provide service to cells that are up to 35
miles across
Pizza box (13 x 13 inch) directional antennas are mounted
at receiving location
33
MMDS Pizza Box Antenna
34
Second Generation MMDS
Work is underway for Second Generation
MMDS


Stronger signal will eliminate line-of-sight
requirement, increase coverage in cell, and
simplify antenna installation
Speeds may reach up to 9 Mbps downstream
and 2.0 Mbps upstream
35
Advantages of MMDS
Advantages
Signal strength—low frequency MMDS
RF signal travels farther and with less
interference than high-frequency LMDS
RF signals
Cell size—seven times larger than area
covered by LMDS transmitters
Cost—MMDS is less expensive than LMDS



36
Disadvantages of MMDS
Disadvantages



Requires direct line-of-sight—makes installation
difficult and eliminates locations blocked by
taller obstructions
Security—Unencrypted transmissions may be
intercepted and read
Limited markets—available in limited areas in
USA
37
CABLE TV IS GOING WIRELESS
38
MMDS - Introduction
• Broadband wireless technology
• Used for Satellite TV signal transmission
– MMDS is also known as Wireless Cable
• the frequency range used is
– 2.1 to 2.7 GHz.
– In US 2.5 to 2.7 MHz (200MHz Band width)
• Maximum coverage area is about 70 Km
• Maximum transmitter power is about 100 watts.
39
MMDS - Introduction
• Maximum no of analog video chls that can be transmitted
in the Band is 33 analog video channels which were 6 MHz
wide.
• But in the same band, about 99 Digital video chls can be
transmitted
• The MMDS frequency band has room for several dozen
analog or digital video channels, along with narrowband
channels that can be used by subscribers to transmit
signals to the network.
– The narrowband channels were originally intended for use in an
educational setting (so-called wireless classrooms).
40
42
What is Wireless LAN / WiFi
43
WiFi is the wireless way to handle networking
It is also known as 802.11 networking and wireless
networking.
The big advantage of WiFi is its simplicity.
You can connect computers anywhere in your home
or office without the need for wires.
 The computers connect to the network using radio
signals, and computers can be up to 100 feet or so
apart.
44
WLAN (WiFi), IEEE 802.11
• Wireless Ethernet standards
– IEEE 802.11
• The Initial release of the standard capable of
transmissions of 1 to 2 Mbps and operates in 2.4
GHz band .
– IEEE 802.11a
• Capable of transmissions upto 54 Mbps and operates
in 5 GHz band .
– IEEE 802.11b
• Capable of transmissions of upto 11 Mbps and
operates in 2.4 GHz band .
– IEEE 802.11g
• Capable of transmissions upto 54 Mbps and operates
45
in 2.4 GHz band
46
47
802.11 range Comparisons
48
Wi-Fi in Metro Access
• Wifi was originally designed to replace
wired last mile (Indoor Ethernet). However
operators are trying to use Wi-Fi in Metro
Access environment (Outdoor Ethernet).
Although not designed for outdoor use,
operators are deploying two different
approaches to use Wi-Fi as Broadband
Metro Access.
– Wi-Fi with directional antenna
– Wi-Fi with a mesh-network topology
49
Increasing 802.11 Range Using Directional Antennas
802.11 Last Mile Networks
Proprietary
Solutions
Wi-Fi Subscriber Station
With High-Gain Antenna
Ethernet
Internet
Wi-Fi
Telco core
network
Or private
(fiber)
network
Wi-Fi
Internal Access
Point with hub
Ethernet
Customer Premise
(Home, Business or HOTSPOT)
Wi-Fi Access Point
With High-Gain antenna
50
HOT SPOT
•A hotspot is a connection point for a WiFi network.
•It is a small box that is hardwired into the Internet.
•The box contains an 802.11 radio that can
simultaneously talk to up to 100 or so 802.11 cards.
•There are many WiFi hotspots now available in
public places like restaurants, hotels, libraries and
airports.
•You can also create your own hotspot in your home,
as we will see in a later section.
52
Adding WiFi to a Computer
•Buy a 802.11a, 802.11b or 802.11g network card.
• For a desktop machine, install the card inside the machine, or
a small external adapter that connect to the computer with a
USB cable.
•For a laptop, a PCMCIA card that is slide into a PCMCIA
slot on the laptop. Or buy a small external adapter and plug
it into a USB port.
•Install the card
•Install the drivers for the card
•Find an 802.11 hotspot
•Access the hotspot.
53
What is WiMax?
• Standards-based wireless technology that
provides high throughput broadband
connections over long distances.
• WiMAX. WiMAX is short for Worldwide
Interoperability for Microwave Access, and
it also goes by the IEEE name 802.16.
55
WiMax would provide:
The high speed of broadband service
Wireless rather than wired access
Broad coverage like the cell phone network instead of the
tiny little hotspots of WiFi
WiMAX could replace cable and DSL services, providing
universal Internet access just about anywhere you go
turning your computer on will automatically connect you to
the closest available WiMAX antenna.
56
A WiMAX system consists of two parts:
A WiMAX tower, similar in concept to a cell-phone tower
A single WiMAX tower can provide coverage to a
very large area -- as big as 3,000 square miles
(~8,000 square km).
A WiMAX receiver - The receiver and antenna could be a
small box or they could be built into a laptop the way WiFi
access is today
57
WiMAX transmitting tower
58
59
WiMAX actually provide two forms of wireless service :
1.Non-line-of-sight, WiFi sort of service, where a small
antenna on your computer connects to the tower. In this
mode, WiMAX uses a lower frequency range –
2 GHz to 11 GHz
2. line-of-sight service, where a fixed dish antenna
points straight at the WiMAX tower from a rooftop or
pole. Line-of-sight transmissions use higher
frequencies, with ranges reaching a possible 66 GHz.
60
IEEE 802.16 Specifications
Range - 30-mile (50-km) radius from base station
Speed - 70 megabits per second
Line-of-sight not needed between user and base
station
Frequency bands - 2 to 11 GHz and 10 to 66 GHz
61
THANK YOU
62