For more info, contact:
Dana Spiegel

or
Jim Youll

What is Rooftops?
Rooftops is a meeting place - mostly online and (historically) offline - for people interested in community-supported, sustainable urban wireless networks. It is not a project so much as a discussion. However, most of the participants in the mailing lists are active in community wireless projects here and elsewhere.

Rooftops@Media is presently an archive of past work, and an ongoing low-traffic mailing list for people with an interest in community wireless. Rooftops does not build, operate or provide wireless networks in the Boston area (though many of the list members are involved in wireless projects in Boston and elsewhere).

To find a free wireless network near you, check out http://nodedb.com/.

The MIT Wireless Forum is a presentation group. They hold monthly talks about wireless technology (cell, wifi, new technology): http://www.mitwf.org/

Roofnet is a research initiative at MIT: http://pdos.lcs.mit.edu/roofnet/

The organizers of this group have graduated from MIT but the mailing list and site are being maintained because (of course) we're all still interested in this topic...

Goal...
Discuss what it would take to create a self-supporting wireless net to cover an area such as the Boston Back Bay, Beacon Hill and south Cambridge (MIT environs) with the ability to expand into the surrounding regions through the efforts of interested people in those regions. The network should grow into new areas as individuals power up new wireless nodes. The nodes could serve not only the individual node owner, but others in the immediate area such as a building (?) or city block (?)

The overall system should be financially and technologically self-sufficient. It should allow people to join the Internet generally without recourse to wireline carriers, and without substantial work beyond the purchase and installation of the node. We presume a mix of volunteer labor and paid staff.

We selected the "place" above because...
(1) MIT people are familar with it (we can even go look at it; many of us live in there somewhere)
(2) It presents a variety of complications:

• high population density in Boston side
• ... separated by brick buildings with varied heights and visibility
• ... with a big empty space - the Charles River - in the middle
• ... dividing Boston from people in wood frame housing of consistent height in Cambridge
  

Technologies are changing rapidly. There are many opinions (and several partly- implemented projects) from the community-hacker and wireless-vendor camps. Possibly, the technology required to make the above a reality does not yet exist, or appears at too high a price point.

The goal is not to design a wireless system for one place, but to expose viable frameworks for economicals architectures that function in the problem-place and area also usable "generally everywhere" without the startup overhead of a custom system.

What are the device/architecture/philosophy combinations that could permit such a network to grow by grassroots effort and willpower? What are the basic "tools" that can be plugged together to make generally-usable systems? Are there fundamental physical limits in present technologies that make some attractive designs implausible? What future technologies can make this a reality?

We want to survey current approaches using now-available technologies for wide-area (blanketing large contiguous regions) and long-range (spanning gaps) wireless technologies by some of the following means, or whatever seems interesting to participants...

• case studies of past and present community wireless projects
• discussions of successful wired, community-supported nonprofit ISPs
• technical analysis of what _can_ be done with off-the-shelf hardware
• sketches of original architectures for wireless urban Internet services, considering cost, capacity, feasibility, and ease of adoption
• discussion and consideration of the societal and economic implications of an available-to-all moderate-capacity wireless data infrastructure everywhere.

MIT Roofnet is an experimental rooftop wireless network testbed for the Grid Ad-Hoc Networking Project in development at MIT LCS 's Parallel and Distributed Operating Systems group. The goal of our project is to build a production-quality self-organizing network capable of providing Internet service while researching scalable routing protocols.

MIT Wireless Forum
http://www.mitwf.org/

NYC Wireless (MIT alums)
http://www.nycwireless.net

http://www.boingo.com/

Simputer low cost access device

./verizon.html

./starbucks.html

./DSL_failures.pdf

Our meeting featuring Simson Garfinkel, July 2001
(at Simson's request, no recording was made)

Presentation and discussion with Simson Garfinkel. Simson is Chief Technology Officer of Sandstorm Enterprises, Inc., a columnist for Technology Review, a frequent contributor to Salon, and a freelance technology writer. He is also the Chief Scientist at Broadband2Wireless, a Boston based wireless networking company.

This meeting is free and open to the public

Wednesday, July 11, 2001
6pm - 8pm
Room E15-054 (Media Lab lower level)

Food will be served

Simson Garfinkel will talk about the issues faced by Broadband2Wireless, a company that wanted to provide wireless networking in the Back Bay/Beacon Hill/South End areas.
He will discuss:
1. Who I am (background & bio)
2. What BB2W tried to do.
3. BB2W's technology choices:
a. 802.11 vs. 802.11(b) vs. 802.11(a) vs. HyperLan II
b. Network Architecture: POP to Hub to Microcell to Customer
c. Encapsulation and Authorization: Why we decided to use PPPoE and Radius
d. Network II plans: Migration to Moble IP.
4. BB2W's business plan.
a. Understanding the IPO Market: how a company is valued.
= $$ per customer
= Multiples of Revenue
= Immediate vs. long-term profitability.
b. Direct vs. Wholesale Model.
c. Unanticipated changes to model.
d. Why we didn't go for Starbucks, and why I think that was a mistake.
5. What it was like to talk to the VCs.
6. What went wrong.
7. What I see as the future for using unlicensed high-speed LAN equipment to provide Internet access.
8. Future technology, both in terms of hardware, as well as network organization and software.
9. Legal issues involved with creating and sharing wireless networks:
a. "your 802.11 interferes with mine and now I'm going to sue you unless you turn it down"
b. consumer Internet contracts forbid resale/redistribution/sharing the circuit even for free