Dear Colleagues, This discussion may have already closed. Please forgive my tardiness; I have been traveling in the bush, but am keenly interested in this thread, as it pertains directly to what we are doing here in Mali.
We are working with exactly the model that Jeff Buderer described: a central VSAT, with the connection shared by many through a local wireless network. We have found that it is economically feasible on paper at least, and are in the process of rolling out such systems in several locations in Mali. The relevant constraint is how to share the bandwidth with enough people (meaning, efficiently) to make it affordable for each one without completely bogging down transfer speeds. (It is a classic maximization problem: maximize number of subscribers, subject to a bandwidth constraint.) We have encountered a few issues. First of all, here in Mali, Yahoo has been so successful in gaining market presence that most people think that an email address MUST end in "@yahoo.fr", which means that every email must go through servers in France, even the ones going to the guy in the office next door. This consumes a LOT of bandwidth. We are encouraging the use of local "systemes de messagerie" (local mail servers) that collect emails and send them out in bursts during periods of low bandwidth usage, such as at night. Thus, while email is not as instantaneous as we in the developed world are used to, this system is still light-years ahead of the present system of word-of-mouth and donkey-cart. I must add, however, that due to on-the-ground political realities here, we find ourselves forced to make the VSAT-and-wireless-network system work ex post facto, and we are doing this in many areas where VSAT would not have been our first choice, but rather is a system that has been selected by other well-intentioned though misguided donors. I share the concerns of many who have posted to this discussion board that all we are doing is subsidizing market access for European satellite companies that had previously determined that it was not otherwise economically viable for them to provide access to these areas. It's the classic story of the $20 bill lying on the sidewalk. If the system is not well thought out and correctly designed, the net result will be to remove value from rural communities for repatriation to the developed world. As a final note to those considering VSAT systems, please note that not all VSATs are created equal, and thus have a BIG impact on the economic viability of a project. (For those of you who are more technically-oriented than I, please forgive the layman's explanation to follow.) Not only whether or not the bandwidth is shared, but also how it is shared, makes a huge difference. It has to do with the size of the packet that the bandwidth can handle. I just think of it as a bottle with stones in it versus a bottle with sand in it. Since the grains of sand are so much smaller than the stones, you can pack them together more tightly, and can thus put more actual mass inside the bottle. (And, to continue the analogy, the sand would flow more smoothly out the mouth of the bottle than would the stones.) Similarly, if a shared bandwidth can only be divided in inflexible, discrete packets, large downloads will take a longer time than under a more flexible system. ------------ ***GKD is solely supported by EDC, a Non-Profit Organization*** To post a message, send it to: <[EMAIL PROTECTED]> To subscribe or unsubscribe, send a message to: <[EMAIL PROTECTED]>. In the 1st line of the message type: subscribe gkd OR type: unsubscribe gkd Archives of previous GKD messages can be found at: <http://www.edc.org/GLG/gkd/>
