Wireless - Microwave and laser
A very economical option for many businesses with Full, Near or Non Line of Sight between sites they own or rent is to use microwave or laser networking. Many organisations are usually stuck paying Carriers often large recurring fees for bandwidth which still doesn't meet their needs for most LAN applications. It can be quite frustrating paying for bandwidth that still only provides less than 10Mbps of bandwidth, often requiring an application layer solution such as Terminal Services to run some applications.