Workplan › Work Package 2

WP2: Network Architecture and product specification

Leader Participants

WP2 defines the future network architectures of backhaul and access based on hierarchical PTMP principle. It deduces the specifications of the "product" (antennas & radios) of the Net Head, Relays Nodes and Terminals. Link budget, performances (throughput, capacity and availability), deployments (topology and ranges), layers (frond end, modems, routing, management and security) will be provided. These descriptions will feed WP3-WP4 & WP5 and precise the target objectives of these work packages. The architectures will serve to define the integrated product in WP6 and the test platform in WP7.

Network definition

SARABAND architecture is a hierarchical, point to multipoint (PMP) IP-based network composed of nodes linked by radio transmissions, and remotely managed by a backhaul network management system (NMS) instance. Figure 1 shows the proposed architecture for the network backhaul.

Figure 1

Figure 1. Network Architecture

From the Fibre optics Point of Presence (PoP), the radio backhaul network uses ultra wide band radio configured for PMP. The covered areas are served by a spectrum bandwidth ranging from 250 MHz to 1 GHz (in the Q-band). These radio transmissions are composed of a multiplex of channels, aggregating several 100 Mbps half-duplex (TDD) channels to provide the required throughput, up to 2 Gbps half-duplex per 1 GHz radio transmission. Typical link capacity is up to 200 Mbps which can either be dedicated to MNO backhaul or shared in the case of access solutions for consumers and enterprises.

The network is composed of two main types of nodes:

Network element specifications

In order to specify the radio and antenna parameters required to guarantee the expected capacity and throughputs, we first built a complete model of the system TH-NTE including all gain and losses of the sub-assemblies, the propagation model, antenna diagram, channelization isolation, etc. This model is the basis of the NMS: when internal product parameters and position of terminal (network configuration) have been introduced, the model optimizes and configures the tuning parameters (modem frequencies, powers and Tx Rx variable gains). As a result the NMS displays the C/N and relevant acceptable order of modulation which leads to throughputs.

By using this model, we obtained the target parameters on the antenna and radio modules to meet operators' requirement and obtain the required performance of the network. These specifications are summarized in Table 1 and 2.

Table 1

Table 1. Target parameters of the radio modules and antennas of TH-RN

Table 2

Table 2. Target parameters of the radio modules and antennas of NTE

These results point out that TH-RN antennas should have a 36-dBi gain, RN-NTE a gain of 24 dBi and NTE antenna a gain of 30 dBi. To obtain the target gains on each network segment, novel antenna technology in Q-band will be developed in WP3 and WP4.