The last mile or last kilometer is a term widely used in the telecommunication, energy and transportation industries to deliver services to retail customers; specifically, it refers to the portion of the network chain that physically reaches the end-user’s premises. The word mile is a metaphor because the last mile of a network to the user is conversely the first mile from the user’s premises to the outside world when the user is sending data or initiating a transport service.
The Speed Bottleneck in networks occurs in the last/first mile; bandwidth effectively limits the data that can be delivered to the customer because networks have relatively few high capacity trunk channels branching out to feed many final mile clients. The final mile links, being the most numerous and thus most expensive part of the system, as well as having to interface with a wide variety of user equipment, are the most difficult to upgrade to new technology. Phone trunk lines that carry calls between switching centers are made of optical-fiber but the last mile is a technology which has remained unchanged for over a century since the original laying of copper phone cables.
The term last mile has expanded outside the communications industries to include other distribution networks that deliver goods to customers, such as the pipes that deliver water and natural gas and the final legs of mail and package deliveries. The problem of sending any given amount of information across a channel can therefore be viewed in terms of sending Information-Carrying Energy ICE. For this reason, the concept of a pipe or conduit is relevant for examining existing systems.
conduits that carry small amounts of a resource a short distance to physically separated endpoints
Cost and Efficiency the high-capacity conduits in these systems tend to also have in common the ability to efficiently transfer a resource over a long distance. Only a small fraction of the resource being transferred is wasted or misdirected. The same cannot be said of lower-capacity conduits; this has to do with efficiency of scale. Conduits that are located closer to the end-user, do not have as many users supporting them; resources supporting these smaller conduits come from the local area. Resources for these conduits can be optimized to achieve the best solutions, however, lower operating efficiencies and greater installation expenses can cause these smaller conduits to be the most expensive and difficult part of a distribution system.
economies of scale increases of a conduit’s capacity are less expensive as the capacity increases
The economics of information transfer an effective last-mile conduit must:
Deliver signal power, must have adequate signal power capacity;
Experience low occurrence of conversion to unusable energy forms;
Support wide transmission bandwidth;
Deliver high signal-to-noise ratio, low unwanted-signal power;
Provide nomadic connectivity.
In addition, a good solution to the last-mile problem must provide each user high availability, reliability, low latency and high per-user capacity. A conduit which is shared among multiple end-users should provide a correspondingly higher capacity in order to properly support each individual user for information transfer in each direction.
Optical fiber offers high information capacity and is the medium of choice for scalability given the increasing bandwidth requirements of modern applications. Unlike copper-based and wireless last-mile mediums, it has built-in future capacity through upgrades of end-point optics and electronics without having to change the existing fiber infrastructure.
optical fiber is the future of local and regional commerce