ADCP-75-210 • Issue 1 • March 2007

1.2System Function

The NXD Distributed Antenna System (DAS), in which the RAN is the remote component, is a multi-frequency, multi-protocol RF access network providing microcellular Cellular and PCS coverage via a distributed RF access system. In a typical configuration, such as shown in Figure 2, multiple RANs are connected to a central Hub where multiple Base Transceiver Station (BTS) interfaces are located. Signals received at the Hub are distributed to the RANs in digital form by way of a fiber optical link. Within the RANs, the signals are converted from digital to RF format to be transmitted from the RAN antennas. Signals also travel in a reverse direction, from the RANs to the Hub, with a reverse data conversion.

Physically, the DAS consists primarily of electronic modules located in the Hub and RANs. At the Hub, these modules are mounted in an equipment rack typically housed in a common telecommunications structure with the base station electronics for Wireless Service Providers (WSPs), either in the same room or nearby. These modules include high power attenuators, base station modules, a power distribution unit, an Ethernet hub, a Hub reference module, an RF chassis, and one or more digital chassis. The RAN electronic modules, mounted in the RAN cabinet, perform the remote system functions of optical to RF data conversion and RF access. These modules are described in subsequent topics within this product description. Digivance Element Management System (EMS) software, running on a computer located at the Hub, provides a graphical user interface to monitor system performance.

Radio

Access

Node

Digital

Fiber

RF

SIGNALS

Distribution Hub - EMS Server, located on Hub Master, monitors Hub Nodes and RANs

WIRELESS

 

 

 

 

 

 

 

 

SERVICE

BTS

 

BTS

 

BTS

 

BTS

 

PROVIDERS

 

 

 

 

 

 

 

 

 

 

 

 

(WSPs)

 

 

 

 

 

 

 

21013-A

 

 

 

 

 

 

 

 

 

Figure 2. System Function

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© 2007, ADC Telecommunications, Inc.