Transcript Study on Technologies for Communication in

Study on technologies for
communication in rural areas
Janak Chandarana (05329R04)
Sravana Kumar K (05329034)
Guide: Prof. Sridhar Iyer
KReSIT, IIT-Bombay
Problem Definition
• One communication line which is shared
by large number of people within small
range of geographical area.
• Communication line can be PSTN
telephone line, GSM or CDMA.
• We need to use this Single line across
whole area for better utilisation of
communication.
Problem Definition (cont.)
• We need to have intranet, which will goes
everywhere in the village.
• The Intranet can be wired or wireless.
• Once we have the intranet and
communication line, then we need to
extend this line to entire intranet.
• Motivation
– Real Life problem
– Urgent necessity
– Convergence of VoIP, WiFi, PSTN and PBX
• Contribution
– Feasible and affordable solution
– Solution is applicable to many Indian villages
– Working solution
– People are using it !!
Existing Solution for given problem
• Conventional PBX
– Expensive
– Cables are not so good communication
medium for a given problem
– Complex
– Lot of manual work
• GMRS
– Can not interface with outside world
Study of various deployment
Option
• Selection of communication medium to
communicate with world
• Selection of medium for intranet through
which Internal communication can be
established
• Interfacing communication line with
intranet
Available Communication medium
• Telephone Line
– Advantages
• Easy to deploy
• Telephone Instruments are cheap and easily
available.
• Conversion from telephone signal to any other
signal is relatively easy than any other medium.
• Ease of setup and use
– Disadvantages
• No mobility for fixed telephone landline.
• Re-configuration is really hard once installed
Communication medium (cont)
• GSM
– Advantages
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Mobility within village
Roaming for outside use also.
Easy to deploy (no landline installation)
We can move entire setup for any other village
– Disadvantages
• power consumption is high (need to recharge
batteries.)
• Recurring cost of billing is high
• Not so easy to convert to any other format (for
example GSM to VoIP)
Communication medium (cont)
• CDMA
– Advantages
• Mobility within village
• Signal can be transmitted over greater distances, it
may give reception in more remote or rural areas
where a GSM phone does not pick up a signal
• Roaming with soft-handoff
• Easy to deploy
– Disadvantages
• Hard to convert to any other format (for example
CDMA to VoIP)
• Mobile handset cant be used for GSM providers.
• Higher cost
Available option for intranet
• Wireless LAN
– Advantages:
• Deployed without cabling, potentially reducing Installation effort
• Supports mobility
• WiFi is a global set of standards. Unlike cellular carriers, the
same WiFi client works in different countries around the world.
– Disadvantages:
• Power consumption is fairly high compared to some other
standards
• Battery life and heat is a concern.
• limited range.
• Interoperability issues between brands or deviations in the
standard can cause limited connection or lower throughput and
speeds.
Available option for intranet (cont)
• 802.3 based Ethernet
– Advantages:
• It strikes a good balance between speed, cost and
ease of installation.
• Wide acceptance in the computer marketplace and
the ability to support virtually all popular network
protocols.
• Almost no packet drop.
• Cheap devices and media.
– Disadvantages:
• Its fixed Installation. Once setup, Its really hard to
re-configure.
• If wire gets disrupted, we need to replace cable.
Available option for intranet (cont)
• corDECT
– Advantages
• The capital and operational costs for running the
corDECT system is low.
• The system's components are designed to work in
harsh environment
• As the power consumption of the corDECT
exchange is very low, investments on UPS would
also be low.
– Disadvantages
• It is yet to be commercially introduced in India by
the DoT
Available option for Intranet (cont)
• GMRS
– Advantages;
• There is no cell site, no telephone operator and no
roaming charges.
• Two-way radio communication is practical and fun.
• No centralized AP needed.
• P-2-P kind of communication.
– Disadvantages:
• Not compatible with other Networking standard.
• Can not interface with computer.
• Problems of licensing with government.
Requirements
• Our Solution for a given problem has
following requirements.
– Hardware Requirements:
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Access Points
Antennas
Adapters
Gateways
PCI cards
Switches
Ethernet Cables
Requirements (cont.)
-VoIP Clients
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WiFi VoIP Phones
Laptops
Desktop PCs
Simputers
– Software Requirements
• Asterisk Server
• Softphones
– SJ Phone
– X-lite Phone
Access Point
• Requirements:
– 802.11
– Potentially excellent LAN performance, especially
with careful configuration and placement
– Easy to configure (GUI support)
– Should Support external Antenna
– Can afford one time higher CAPEX cost
– least OPEX cost
– Low power consumption
Access Point
• Suggested Solution:
– Model: The D-Link DWL-2100AP Access Point
– Wireless Frequency Range: 2.4GHz to 2.4835GHz
– Wireless Signal Range
• Indoors: Up to 100 meters
• Outdoors: Up to 400 meters
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Wireless Transmit Power: 15dBm
Power Input: Ext. Power Supply DC 5V, 2.0A
Dimensions: 142mm X 109mm X 31mm
Weight : 200g
cost: Rs. 7,000
D-link Access Point
Antenna
• Requirements:
– Signal Range:- 200 mts or more
– Should work in partially Line of sight also
– Less CAPEX cost
– Minimum OPEX cost
– Antennas should give excellent throughput
over large areas.
– Effect of direction on Signal strength
Antenna
• Solution
– Model: D-Link ANT24-0801 8.5 dBi Directional
Wireless Antenna
– Frequency Range: 2300MHz to 2500MHz
– Power Handling: 50W
– Antenna Range: Up to 150 meter
– Dimensions: 120mm X 120 mm X 43mm
– Weight: 300g
– Cost: Rs. 9,500
D-link external antenna
VoIP Gateway
• Requirements
– It should convert analog telephone signal to
VoIP
– Compatible with asterisk server.
– should supports SIP
– Telephone line should work even when
gateway is switched off.
– Should consume less power
VoIP Gateway
• Solution
– Model: Sipura VoIP Gateway SPA-3000
– One RJ-45 port and One RJ-11 port
– Power Consumption: 50 watts
– Box dimensions: 183mm X 152mm X 64mm
– Weight: 490g
– Cost: Rs. 6,500
Sipura SPA-3000 VoIP gateway
VoIP-PSTN Adapter
• Requirements
– It should have at least one RJ-45 pin as well
as one RJ-11 pin
– It should support multiple telephone
instruments
– Support for Session Initiation Protocol (SIP)
– Lower CAPEX and OPEX cost
– Compatible with asterisk server
VoIP-PSTN Adapter
• Solution:
– Model : LinkSys PAP2-NA 2-Port VoIP
Gateway SIP FXS Adapter
– One RJ-45 Port , two RJ-11 port
– Supports both DHCP and SIP
– Power Supply: 5V DC 2.0A
– Dimensions: 101mm X 101mm X 15mm
– Weight: 140g
– Cost: Rs. 4,500
LinkSys PAP2 Adapter
PCI VoIP cards
• Requirements
– It should converts the analog telephone signal
to VoIP
– It should have one RJ-11 FXO port (and/or one
FXS port)
– Easy to configure (Preferably Plug and play
feature)
– Compatible with Desktop PC’s motherboard
– Support Asterisk PBX
PCI VoIP cards
• Solution
– Model: Digium X100P FXO clone PCI card
– Supports Asterisk PBX
– One FXO pin and One FXS pin
– Cost: Rs. 2600
Digium X100P clone PCI card
Client Side Devices
• Requirements
– Less power consumption
– Higher portability
– Easy to install
– Low price
– High Tx-Rx antenna
Client Side Devices
• WiFi Phones:
– Model: Linksys WIP300 Wireless-G
IP Phone
– Operates in the 2.4GHz band
– Supports 802.11g and the VoIP SIP
protocols
– High Resolution Color LCD screen
– USB Charger Interface
– Cost: Rs. 6000
Client Side Devices (cont.)
Simputer
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Model: Amida 2200 Simputer
It supports SIP
Less Power consumption
Nice VoIP client software .
More Portability
Multi purpose device
can be used in education
Cost: Rs. 15,000
Client Side Devices
Soft phones:
– should allows voice
transmission on LAN
– support SIP
– Easy to configure
– Examples:
• SJ Phone
• X-Lite Phone
Asterisk soft PBX
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Asterisk is open source software PBX
It runs on Linux
It supports SIP
Runs on almost all hardware
All the functionality of conventional PBX
Fast, robust and free!
Case Study
• Timbaktu Collectives
– Timbaktu Collective is a registered voluntary
organization that was initiated in 1990
– Timbaktu is surrounded by hills and is far from any urban
area in Andhra Pradesh, India.
– They don't have any GSM or CDMA coverage.
– Telephone department had provided one telephone line
to Timbaktu.
– They don't have Electricity supply.
– They are using solar power.
– Timbaktu has lot of trees in between which may become
obstacle for wireless communication.
VoIP based Solution
• Phase 1(dec-05):
– We had identified 802.11 WiFi as Intranet solution for
communication.
– We had deployed Asterisk Server over Linux machine
and It was connected with Access Point over WiFi.
– All other clients like simputer, soft-phones and
LinkSys Adapters were communicating with Asterisk.
note: Trees which comes in between antenna and client attenuate signals greatly.
VoIP based Solution
• Phase 2(feb-06):
– We had thought of Ethernet cables as medium for
some part of village which are nearer to
communication line.
– Wireless had very higher rate of packet drop which
was bigger constrain for voice communication.
– VoIP asterisk server was also connected through
access point which provides connectivity to wireless
VoIP clients such as simputer.
– We had VoIP gateway which can serve
incoming/outgoing calls.
VoIP based Solution
• Phase-3 (future plan)
– Deployment of hybrid solution which use
Wireless as well as Ethernet based solution
– Stand alone hardware(3 in 1) which has VoIP
gateway, asterisk PBX and VoIP adapter in a
single box.
– Low cost wireless VoIP client (like GMRS)
which can work with 802.11
Conclusion
• Every time we don’t need best “technical”
solution.
• But we need affordable, feasible, working
and quickly available solution which is
easily acceptable.
• VoIP has great potential for Indian rural
development.
• Proposed 3-in-1 box can change telecom
market in India largely.