y will locate network equipment on premises in an office building. To back-haul traffic to a central office, however, they install a line-of-sight, microwave antenna, or other wireless transmitter, on the roof, which sends traffic to a centralized relay station. Such technology is also being considered for rural and developing regions because it eliminates the need for digging trenches and installing underground conduits. WLL providers can also offer a full range of services including voice, data and video. Digital Subscriber Line (DSL) Wholesalers. DSL wholesalers are companies that specialize in providing DSL service components to IICs such as ISPs, which in turn offer retail DSL services to end-users. ILECs, as mentioned earlier, control the local loops and end offices that serve businesses and residences. DSL operates over these local loops. DSL wholesalers have automated most of the ordering, provisioning and trouble management processes needed for dealing with an ILEC. These wholesalers also install the end-office equipment and manage the co-location agreements with ILECs that are necessary for DSL deployment. In short, these companies have simplified the processes associated with DSL and reduced the capital expenditure burden for DSL retailers, many of which cannot afford to purchase and install DSL serving equipment or lease the end-office space to house it and link it to ILEC or other backbone networks. We will take a closer look at DSL wholesalers and how they operate when we discuss the Internet infrastructure supply chain in Chapter 3. For now, it is necessary to understand that these companies are essentially the middle men Chapter 1 - Introduction to IICs and OSS of the DSL business and have helped create a viable market for DSL services by minimizing complexity for retailers. Managed Service Providers (MSPs)/Hosting Service Providers (HSPs). MSPs or HSPs provide managed data centers to businesses that wish to outsource their information technology (IT) base. With the data center linked to customer 