Study on technologies for communication in rural areas Janak Chandarana (05329R04) Sravana Kumar K (05329034) Guide: Prof. Sridhar Iyer KReSIT, IIT-Bombay.

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

• 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:

• Access Points• Antennas• Adapters• Gateways• PCI cards• Switches• Ethernet Cables

Requirements (cont.)

-VoIP Clients• 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

– 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– 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

• 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.