User's Manual

CHAPTER 3. System Structure

3-4

M2DA-A

The M2DA-A is the software that carries out the SPI-2L10 routing protocol function.

The M2DA-A operates and maintains the SPI-2L10. It makes it possible for the SPI-2L10

to interface with the ACR and provides a communication path between processors within

the system. Moreover, the M2DA-A generates reference clocks, supplies them to the lower

hardware blocks, and carries out the signal processing function for subscriber signals.

From a functional standpoint, the M2DA-A consists of the following.

y Network Interface Part

The Network Interface part of the M2DA-A interfaces with the ACR via Fast Ethernet,

and provides the following interfaces and ports.

− One 1000 Base-LX port

y Control Part

The Control part of the M2DA-A performs the topmost control of the SPI-2L10.

It downloads the software in the system, manages the status of all hardware/software,

and reports it to the WSM via the ACR. In addition, the Control part assigns the trunk

lines and channel resources within the system and performs call processing, system

operation and maintenance, and TDD signal control.

y Signal Processing Part

The Signal Processing part of the M2DA-A is equipped with a modem that supports

the IEEE 802.16/16e Mobile WiMAX standard physical layer (PHY).This modem

processes OFDMA signals under control of the Control part.

That is, the Signal Processing part modulates the packet data received from the ACR

and sends them to the RF Processing part. In the other direction, the Signal Processing

part carries out the Automatic Gain Control (AGC) function on the data received from

the RF Processing part, converts them to the format defined in the specifications of the

IEEE 802.16/16e Mobile WiMAX standard physical layer.

The Signal Processing part can support 2-branch Rx diversity, by default, and, further,

2Carrier/Omni 2Tx/2Rx SM/STC-MIMO.

y GPS Reception and Clock Distribution Part

The M2DA-A can receive synchronization signals via the GPS or IEEE 1588 master.

The M2DA-A interfaces with the Universal Core Clock Module-Plus (UCCM-P) to

receive GPS signals. The UCCM-P generates reference clocks (PP2S, 10 MHz, TOD)

using the signals from the GPS so that each block of the SPI-2L10 can operate with a

synchronized clock system.

The reference clocks generated by the UCCM-P are regenerated by the CPLD and PLL

within the M2DA-A as the clocks necessary for each block and they distribute those

regenerated clocks to their corresponding blocks. These clocks are used to maintain

internal synchronization in the SPI-2L10 and operate the system.

If GPS signals, which have been provided continually, are not provided due to a fault,

the UCCM-P uses its previously learned ability to carry out the holdover function

which provides clocks in the locked state for a specific period of time (24 hours).