User Manual

ADCP-XX-XXX • November 2000 • Section 2: WMTS Description
Page 2-4
 2000, ADC Telecommunications, Inc.
The Wireless Modem Termination System uses a modular design that includes:
• WMTS chassis with integrated backplane
• Host cards (primary and backup)
• Up to eight universal cards, which are configured for upstream, downstream or
control/forwarding functions
• One downstream card
• Up to five upstream cards
• Redundant AC power supplies
• Two fan tray assemblies
The WMTS is responsible for setting the upstream bandwidth to its subtending WMU
modems.
2.2 Structure
The WMTS chassis is the core of the Axity system. It contains the host cards, controller and
forwarder (C&F) card and the upstream and downstream modules. The upstream module
contains the universal card and upstream (demodulator) card. The downstream module
contains the universal card and the downstream (modulator) card. The system cards
communicate and handle traffic over a standard internal compact PCI bus.
The host card serves as bus arbitrator, providing system clock and timing. When the WMTS
boots up, the host card initializes all the other system cards, identifying the C&F card. The
C&F card then identifies the downstream and upstream universal cards and downloads the
relevant application software and firmware to the flash memory of each card.
The downstream universal card is connected to the downstream card, which generates the
downstream IF to send data over the wireless channel via the transmitter. The upstream
universal card is connected to the upstream card, which demodulates the incoming IF to obtain
data sent over the wireless channel from the upstream downconverter.
The C&F card, which is connected through the network interface via 100BaseT full duplex
Ethernet port, communicates with the EMS.
The minimal WMTS configuration, which is illustrated in Figure 2-2, contains the following:
• Host card
– For bus arbitration and system clock generation
– System application downloading to the universal cards
• Three universal cards (configured as follows)
– C&F card connected to the switch or router via an Ethernet bus
– Downstream card connected to the modulator to transmit data to WMU
– Upstream Card connected to the demodulator to receive data from the WMU
• Downstream card to modulate data and generate the IF for the RF transmitter