er cables (twisted pairs). However, in certain remote locations, you might consider using wireless local loop or satellite communications as an alternative access loop. These access technologies do not serve the purpose of offering broad- band access to commercial customers located in densely populated metro- politan areas. This is where Digital Subscriber Line (DSL) comes into play. DSL is supposed to provide a connection that is higher than T1 speed in a cost-effective way, but the recent downfall of DSL service providers and equipment manufacturers has dramatically hindered the growth of this access technology. Some customers have been considering wireless access technologies such as microwave, Local Multipoint Distribution Service (LMDS), and Multichannel Multipoint Distribution System (MMDS). These are well-designed access technologies despite the fact that they are not widely deployed by service providers and the performance could vary significantly from location to location. Fiber-optic cables can offer a Chapter 9 tremendous amount of bandwidth, but the question is whether customers need the amount of bandwidth and are willing to pay the cost of fiber installation and the systems required. In addition, the buildout of a brand- new fiber system can take six months to a year even before the customer can benefit from the fiber network. FSOs fit nicely into the arena from a cost and lead-time standpoint. FSO is targeted for customers who require quick provisioning time and high bandwidth that ranges from Ethernet speed (10 Mbps) to OC-3 or OC-12. FSO is an ideal candidate if customers are located in sites near a service provider's backbone. Figure 9-11 shows how the technologies mentioned previously address different market envi- ronments (that is, urban, rural, and remote) based on the transmission rates supported. 100 Gbps Figure 9-11 Addressing different market environments. 10 Gbps OC-48 Fiber Optic Cable 1 Gbps OC-12 100 Mbps Wireless Optics Point-to-Point Microwave 10 Mbps 1 Mbps Frame Relay 0.1 Mbps Pr