The Future Community Network

Onno W. Purbo

At the moment, I connect my home LAN as well as my surrounding neighborhood to the Internet for 24-hour access at 11Mbps. I personally share Rp. 330.000 / month (approximately US$30 / month). In some areas, it may cost as low as US$15/month for 24 hours Internet connection from a house in a neighborhood.

Such low cost 24 hours Internet connection is not possible without the existence of neighborhood networks. The detailed technology can be downloaded from http://sandbox.bellanet.org/~onno/. Those who need advice & technical support can join and ask in English in wifi4d@dgroups.org.

Unlike a normal Community Tele-Center (CTC) or cyber café that connects several computers in a room or a house, in neighborhood network, we extend the LAN cables (RJ-45 UTP cables) to our neighbors. Thus, we basically deploy a campus Wide Area Network based on Ethernet LAN to surrounding neighborhood. 

Since the maximum length of UTP cable is normally around 100-200 meter. We use a hub to relay the signal to the next 100-200 meter. It is basically a tree structure of LAN connection.

To strengthening the cable from any troubles, such as, rat and water erosion, we normally run the cable in a plastic (PVC) plumbing pipe run along the drainage in the neighborhood. 

As more house or computer in the neighborhood connected to the neighborhood network, the investment cost per house can be reduced to a relatively low around US$50-80/house.

Thus, we basically have a simple solution to deploy a low cost broadband campus wide neighborhood area network using off-the-shelf low cost Ethernet LAN technology.

Analyzing the cost to run an Internet infrastructure, it would clearly shown that most of the money actually goes into Indonesian Telco pocket to pay the telecommunication lines, not to mention, current increase in Indonesian Telco’s tariff. It really drives the community to seek solution to build our own network to bypass Telco.

Our next task is to find a low cost broadband connection to the nearest Internet Service Provider within 5-10 km range.

We found that the best low cost solution for such distance is off-the-shelf WiFi equipment. WiFi is basically wireless LAN equipment operates on 2.4GHz or 5.8GHz frequency at typically 1-11Mbps speed.

WiFi is based on IEEE 802.11 standard and originally designed for indoor usage. The default antenna is normally used for 100-200 meter range.

To bypass Telco’s last mile in 5-8 km ranges, we normally unplug the factory default antenna. Replace the antenna using a high gain flat panel or parabolic antenna design for 2.4GHz or 5.8GHz.

Connect the external high gain antenna to the WiFi card via a short 0.5 meters pigtail cable. A pigtail cable has normally SMA connector and N-type connector, respectively. N-type connector is used to connect the high gain external antenna. While, the SMA connector is used for connecting the WiFi card.

Thus, make sure we buy a WiFi equipment with SMA connector for the antenna.

Building low cost home made 2.4GHz antenna is not that difficult, a tincan with 90 mm diameter, and 215 mm length can be easily used as 2.4GHz antenna for 1-2 km distances. It costs approximately US$5-10 per antenna.

Since WiFi is normally run at very low power 30-100mW, to reduce signal loss, we normally enclosed the WiFi equipment in a plastic enclosure and put it on top of 20-30 meters tower. Thus, the distance between antenna and WiFi equipment can be made very short 0.5 meter.

Then run a LAN cable from the back of WiFi equipment along the tower to the PC and neighborhood network at the bottom.

Thus, with a US$100-300 investment, we can have a broadband 11Mbps connection the ISP within 5-10 km ranges.

A typical changes for dedicated 64Kbps 24 hours Internet access in Indonesia is about US$400 /month.

Having 20-30 houses in the neighborhood network, we can easily reach the affordable US$15-40/month/house of operating cost.

The similar movement applies for school network, office network and other type of network. Not surprising to see more than 5000 outdoor WiFi nodes installed in Indonesia.

Having the solution to build an alternative for high-speed metropolitan access network, we need to think on how to build the regional network. We use two (2) main technologies to build our regional network, namely,

•	Satellite backbone. The cheapest solution we can currently get in Indonesia is DVB-RCS satellite backbone sells at US$200-700 at 64Kbps depending on the agreement on providing the satellite ground station.
•	Fiber / microwave backbone rent from cellular operator. The excess capacity of cellular backbone is used to pass our data traffic from city to city. The local ISP is normally rent to backbone and sells it as part of the Internet access to the community.

Another emerging controversial technology is the Internet telephony. 

All will be part of emerging future community based network, that may challenge many paradigm used in today regulatory and policy framework.