New-Tech Europe | May 2017

High-Order Switch Matrices Facilitate Network Infrastructure Testing

Chi Man Shum, Mini-Circuits

Testingcellularnetworkinfrastructure often requires measurement and data collection from dozens – even hundreds – of base stations (BTS) within a test environment. The volume and complexity of signal traffic in these multi-device, multi- user test systems necessitates commensurate capability for routing signals between base stations and test stations. By partnering with customers to lower costs and improve efficiency in high-volume test systems, Mini-Circuits has developed a line of high-order switch matrices supporting a wide variety of switching configurations and control methods. This article will present a case study of a 20 x 6 non-blocking, full access switch matrix used to facilitate signal routing in a cellular

network test system with extensions for other applications. Case Study: A High Order Switching System for Cellular Network Testing A cellular network operator was building a test setup to validate new BTS equipment on their network. The test system needed to evaluate each channel of new BTS nodes to verify they were meeting specifications; it needed to confirm that new equipment worked alongside existing, heterogeneous equipment without adverse interactions; and it needed to allow validation of supported handsets with the new BTS equipment. For this functionality, the customer required a signal routing system to connect 6 independent test stations to any or all of 20 base station

(BTS) channels. The setup needed to allow multiple users to connect to the same BTS if necessary, but also required a control mechanism to limit which test stations could access which BTS. To satisfy these requirements, Mini-Circuits developed the ZT-20X6NB, a 20 x 6 non-blocking full access switch matrix. This bi-directional switch matrix covers the key worldwide telecommunications bands from 600 MHz to 6 GHz and can be programed to connect ports B1 – B6 (shown in Figure 1) to any combination of ports A1 – A20, such that multiple input ports may be routed to the same output port simultaneously. Because of its flexibility, this non-blocking configuration is ideal for multi-user, multi-device test systems of the kind

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