This is a specification of the network architecture, components, and functionality for the Rapid Deployment Radio Network. This specification attempts to be independent of implementation details such as where and how functionality is implemented. Functionality is rated as mandatory, high priority, or optional. Mandatory functions will be implemented, high priority functions may be implemented if time permits, and optional functions have a low probability of being implemented. Within each functional area the relevant standards and proposals are noted as well as assumptions and open issues. The logical system components for the Edge Node (EN) are shown in Figure 1 and the components for the Remote Node (RN) are shown in Figure 2. The components include a high speed radio and directional antenna for EN-EN connections, medium speed radio and directional antenna for EN-RN connections, and a processor with a Linux operating system for configuration and link quality processing.
Figure 1: Edge Node Components.
Figure 2: Remote Node Components.
The implemented system will consist of Edge Nodes (EN) and Remote Nodes (RN) as shown in Figure 13. The RNs are mobile host nodes. A more detailed view of the system is shown in Figure 3. The Edge Nodes (EN) are shown as dashed boxes and consist of at least one Edge Switch (ES) and may contain an ATM Switch. The ES has the capability of switching ATM cells among RNs or passing the cells on to an ATM switch for faster switching for the higher speed EN-EN connections. The anticipated protocol stack for the high speed network is shown in Figure 4. Note that the differences between an ES and RN are that the ES performs switching and has the capability of higher speed radio links with other Edge Nodes.
Figure 3: Edge Nodes and Edge Switches.
A goal of the original design was to keep the wireless component as simple as possible. It would be attached to an existing ATM switch through a single port creating a node which could reside at the edge between a fixed and wireless network. However, well known VCs such as 1 (GSMP) 5 (Q.2931), and 16 (SNMP) would overlap for all remote hosts. It was decided to incorporate switching into the wireless interface, thus eliminating the need for the ATM switch. Because the wireless interface has switching capability, overlapping VC space is not a problem and RN to RN connections at the same base station can be connected directly together without having to go through the ATM switch. A disadvantage of incorporating ATM switching into the wireless interface is that the extra features incorporated in ATM switches, such as topology aquisition, RVCs, LAN Emulation, Switching Agent, etc... will not be avaliable without significant additional development effort.
In order to make the problem more tractable, Sections 2 through 8 focus on a static wireless network, e.g. RNs remain associated with a single ES; no handoffs take place. The remaining sections handle dynamic mobile networks.