Andrew Wireless System NCM843 Benutzerhandbuch

2 Introduction 

 

 

Page 15

 

 
Wireless communication systems provide a two-way information transfer (voice and 
data) between a base station and multiple mobiles within a given area. 
Environmental variables such as physical structures both man-made (buildings) and 
natural (mountains) attenuate signals in the transmission path, which reduce the 
transport signal’s strength. This attenuation leads to a reduction in quality and data 
rate and eventually prohibits the system’s use entirely. The Node M and Node C are 
specifically designed to extend coverage, enhance quality, and increase air-interface 
capacity. 

 

In the downlink (DL), the Node M and Node C picks up signals coming from the base 
station, filters them, amplifies them, and retransmits them to the mobile. In the uplink 
(UL), it picks up signals from the mobile, filters them, amplifies them, and retransmits 
them to the base station. The Node M and Node C constantly monitors the quality of 
the signals passing through it, while simultaneously electronically decreasing 
isolation requirements. 

 
Node M and Node C are primary network elements, capable of enhancing up to 20 
MHz of continuous spectrum. Their primary function is to increase the signal strength 
between multiple mobiles and a base station in areas where basic voice or high-
speed data transmission is not available. They may be used for basic coverage, 
signal reinforcement, and cell shaping, which can increase a network’s coverage 
area, data rate, and capacity. 

 

The Node M is a dedicated UMTS device, but the Node C operates with CDMA 
technology. However, several enhancers operating at different frequencies and 
technologies may share the same hardware (cables and antennas) via a crossband 
coupler. 

 

The Node M or Node C may be set-up locally or remotely. A circuit switch or packet 
data modem may be connected to an integrated controller. This provides the network 
management system with on-demand, alarm generated, or heartbeat monitoring via 
the always-connected packet features. The Node M and Node C have features and 
functions that may be monitored and changed by the operators via a web-based 
browser remotely or locally, or via the SNMP based OMC software platform. The 
graphical interfaces of Node M and Node C provide a setup menu including a setup 
wizard which allows both setup and monitoring capability without any equipment 
required apart from a laptop or PC. 
The Node M and Node C network elements are self-diagnosing, self-adaptive, and 
virtually maintenance-free.