Challenges: wide-area wirelesss NETworks (WANETs)

A WANET is a wireless network where the wireless nodes can be located anywhere over the globe. However, the underlying design is such that the nodes believe they are part of a single-hop or multi-hop wireless network at the PHY and MAC layers. This is accomplished by using Software Defined Access Points (SoDA) that are based on the idea of Software Defined Radio (SDR). For the uplink, each SoDA samples the down-converted channel using an ADC (analog-to-digital converter). The sampled data is then multicast to the other SoDAs via the Internet. At each end-point, the received digital signals from the other SoDAs are summed and sent through the DAC (digital-to-analog converter) and transmitted on a designated channel after upconversion. In effect what we have done is to mix the RF environment at geographically separate locations (albeit with a time shift). This simple technique leads to a whole new model for designing and using wireless networks. Indeed, we can think of these networks as following the end-to-end model where only the end nodes understand the PHY/MAC layers and the access points and Internet serve simply as dumb relays. This paper describes a series of network models that are enabled and outlines the open research challenges.