The Things I Thought I’d Never Do

Sonesh SuranaI290: Designing Rural Computing Applications

Guest LectureNovember 4, 2008

Timeline

Aug 2004: 1 day

Jan 2005:

25 days

June 2005:

24 days

Aug 2005:

21 days

Dec 2005:

37 days

Feb 2006:

6 days

Oct 2006:

20 days

Jan 2008:

12 days

20041 day

2005107 days

200626 days

200812 days

Total146 days

Photo acknowledgment: Francis Kpobe, Ghana

Tower Challenges?

Training Challenges?

“So then we put the separate modem at chimney now the link has been up it means , in Theni router-3 we put the ath1 card and it is focusing the new separate modem at chimney.

We have pointed out one think ie we put the new wireless card in the existing modem(suppose we put the ath1 in , Theni router-3 , already it connected to SBS through ath0) the link quality will be down).”

Power Challenges?

23

Poor Quality Power

Spikes and Swells:

• Lost 50 power adapters

• Burned 30 PoE ports

Low Voltages:

• Incomplete boots

• HW watchdog fails

Frequent Fluctuations:

• CF corruptions

• Battery Damage

Volta

ge R

ange

Number of Instances seen over 6 weeks

24

What about UPS?

“Affordable” UPS systems ($300) are of standby-typePrimary source is gridSecondary source is batteryGood quality power supplied only during outage!

Real Cost of Power

Assume 7W

Monthly CostsGrid: $0.25

UPS + Battery: $6.08 (24X more!!)

50W Panel + Controller + Battery: $8.24

25

Some Results

27

Operational Results

Equipment Supply

Installation

Management

Maintenance

TIER, UC Berkeley

Aravind

Local Vendor

Jan’06 – Jun’06

Migration at Aravind

2007: 5 more clinic links

Jun’07 – Dec’07Jul’06 – Dec’06 Jan’07 – Jun’07

0

500

1000

1500

2000

2500

3000

3500

4000

4500

5000

Jan-

06

Feb-

06

Mar

-06

Apr

-06

May

-06

Jun-

06

Jul-0

6

Aug

-06

Sep

-06

Oct

-06

Nov

-06

Dec

-06

Jan-

07

Feb-

07

Mar

-07

Apr

-07

May

-07

Jun-

07

Jul-0

7

Aug

-07

Sep

-07

Oct

-07

Nov

-07

Dec

-07

Jan-

08

Feb-

08

Mar

-08

Apr

-08

May

-08

Jun-

08

Jul-0

8

Aug

-08

Sep

-08

Kallidakurchi

Srivaikundam

Sholavandan

Tirupovanam

Alanganallur

Andipatti

Periyakulum

Chinnamanur

Bodi

Ambasamudram

Num

ber of Patients

Patient Throughput

90,000 patients screened; vision restored for 15,858

Time in Months (Jan 2006 to September 2008)

Thank You!