McBSC and McTC Architecture

mcBSC and mcTC architecture The major architectural change with the mcBSCand the mcTC is the move from multi-subrack blade system to a few rack mount modules. Depending on the capacity needs, one mcBSC can consist of two up to several modules. A multicontroller module is tightly integrated and has only a few field-replaceable parts. The new Multicontroller HW platform allows new, optimized placement of the BSC and transcoder functionalities in the system.

Functional architecture of the mcBSC Figure 7 shows the general functional architecture of the mcBSC. The functions are distributed in entities of hardware and software. The 1G and 10G interfaces are available for external connections towards site routers. The main functional units of the mcBSC are: BSC signaling unit (BCSU) Marker and cellular management unit (MCMU) Operation and maintenance unit (OMU) Packet control unit (PCUM) Ethernet transmission processing (ETP)

Figure 7:

Functional architecture of the mcBSC

The general ETP functionality contains ETME and ETMA functionalities.

The distributed processing architecture of the mcBSC is implemented by a multiprocessor system, where the data

processing capacity is divided among several processors. Based on the application needs general purpose processing units can be assigned to different tasks. Internal communications (internal messaging) between the functional units of the system is based on Ethernet. The mcBSC functional units are briefly described below:

BSC signaling unit (BCSU) The BSC signaling unit (BCSU) is a TRX-capacity unit of the mcBSC. It performs those BSC functions that are highly dependent on the volume of traffic. The BCSU consists of two parts, which correspond to the A over IP (AoIP) and Packet Abis interfaces. The AoIP interface part of the BCSU is responsible for the following tasks: Performing the functions of SIGTRAN based SS7 signaling Performing all message handling and processing functions of the signaling channels connected to it The Packet Abis interface part of the BCSU controls the air interface channels associated with transceivers and Abis signaling channels. The handover and power control algorithms reside in this functional unit.

Packet control unit (PCU) The PCU unit is an independent processing unit logically connected to the BSCU. The PCU unit performs all the data processing tasks related to GPRS/EDGE traffic. It implements packet switched traffic oriented Gb and Packet Abis interfaces in the mcBSC. The PCU controls GPRS/EDGE radio resources and acts as the key unit in the following procedures: GPRS/EDGE radio resource allocation and management GPRS/EDGE radio connection establishment and management Data transfer Coding scheme selection PCU statistics

Ethernet transmission processing (ETP) In the mcBSC, A and Abis interfaces are connected to an IP network. The ETP functionality terminates all external management, user and control plane IP traffic, handling the Ethernet transmission processing which is related to AoIP and Packet Abis interfaces in the mcBSC. The general ETP functionality contains ETME and ETMA functionalities. With the mcTC implementation, when transcoder is located in the BSS, ETP functionality handles the needed Ethernet transmission processing related to used Packet Ater interface between the mcBSC and the mcTC.

Marker and cellular management unit (MCMU) The MCMU has centralized cellular management functions for controlling cells and radio channels for the mcBSC. The MCMU reserves and keeps track of the radio resources requested by the MSC and the handover procedures of the mcBSC. The MCMU also manages the configuration of the cellular network.

Operation and maintenance unit (OMU) The Operation and Maintenance Unit (OMU) is an interface between the mcBSC and a higher-level network management system and/or the user. The mcBSC can provide full-scale traffic capacity even when O&M interface towards NetAct is disconnected. The OMU can also be used for local operations and maintenance. The OMU receives fault indications from the mcBSC. It can produce local alarm printouts to the user or send the fault indications to NetAct. In the event of a fault, the OMU automatically activates appropriate recovery and diagnostics procedures within the mcBSC. Recovery can also be activated by the MCMU if the OMU is lost. The tasks of the OMU can be divided into four groups: Traffic control functions Maintenance functions System configuration administration functions

System management functions

Functional architecture of the mcTC The general functional architecture of the mcTC is shown in Figure 8.

Figure 8:

Functional architecture of the mcTC

The functions are distributed in entities of hardware and software. The main functional units of the mcTC are: ETP, which is responsible for terminating all external management, user and control plane IP traffic. Transcoding unit (TCU), which implements transcoding and rate adaptation and other media processing functions for the mcTC. Management and control unit (MCU), which implements transcoder control, management and centralized O&M tasks in the mcTC module.

mcBSC and mcTC hardware architecture The mcBSC and the mcTC are based on the Multicontroller HW platform in which motherboard provides the following main functions: Slots for add-in cards Ethernet switch AMC expansion slots Power supply and cooling Add-in cards provides the processing functionality. The mcBSC and the mcTC products efficiently utilize general purpose processing units with SW configurable functionality for control, O&M and user plane as well as for Ethernet transmission processing and transcoding purposes.

External physical interfaces Network interfaces provide external interfaces and the means to execute physical layer and transport layer functions. Any interface can be configured to be used as an Abis, A, Gb or Ater interface. External physical interfaces towards site routers can be either 1G or 10G with relevant SFP modules. In addition to the network interfaces, local area network (LAN) interfaces as well as debugging and maintenance interfaces are provided in front of the module. The controller module front panel is shown in Figure 9.

Figure 9:

Physical interfaces of controller module

Gigabit Ethernet interfaces IP over Ethernet network interfaces with protection possibility are provided in the front panel of the module. One module may contain up to 16 pcs of Gigabit Ethernet interfaces and up to 6 pcs of interfaces, that can be used either in 1 Gbps or 10Gbps speed. All these interfaces use standard SFP and SFP+ (for 10GE) connectors. Interface Type

Gigabit Ethernet

Standard

IEEE 802.3-2005

Physical layer

1000Base-SX

1000Base-LX

1000Base-T

Connections

SFP/LC

SFP/LC

SFP/RJ-45

Number of interfaces

16 + 2 pcs in the node

Table 1:

Interface specifications for network connections and element management

Interface Type

1 and 10 Gbps Ethernet

Standard

IEEE 802.3-2005

Physical layer

1000Base-SX

1000Base-LX

1000Base-T

Connections

SFP/LC

SFP/LC

SFP/RJ-45

Physical layer

10GBase-SR

10Base-LR

10GDirect Attach

Connections

SFP+/LC

SFP+/LC

SFP+/copper

Number of interfaces

6 pcs in the node

Table 2:

Interface specifications for connections to be used either for module interconnects or network connections

LAN/Ethernet for O&M interfaces The local area network interface functions at the rate of 10/100/1000 Mbps using an RJ45 connector located in the front panel.

SW download and SW debugging interfaces One USB type B interface for debugging and two USB type A interfaces for SW download are provided on the front panel.

Serial Port interface Standard RS-232 interface with a RJ-45 connector, used for connection to the Local Management Processor.

External Alarm interface Standard RJ-45 connector, used for collecting external alarm inputs for monitoring purpose.

External Telecom Synchronization interface Two standard RJ-45 connectors, used for external E1, T1, J1, 2.048 MHz, and 1.544 MHz input and output reference. mcBSC synchronization connectors are used for maximum two external inputs (multibox or unibox) and remaining connectors are used for chaining box synchronization.

External HD cross connection Standard SAS connector, used for cross connecting hard disks between two controller module boxes.

External Packet Synchronization Interfaces Optional Multicontroller Packet Timing Unit (PTUM) is used for mcBSC packet synchronization. This unit implements Ethernet Packet synchronization IEEE1588v2 PTP protocol and Synchronous Ethernet (SyncE) for physical layer synchronization. It can be used in master or slave modes. Packet Synchronization interfaces are available with BSAC-A AMC card. Two Standard SFP connectors, used for external 100M/1GE Ethernet providing IEEE 1588 or Synchronous Ethernet timing. Two Standard RJ-45 connectors, used for external E1, T1, J1, 2.048 MHz input (and output) reference or GPS input.

Element Management 1GigE Interface One 1 GigE (1000Base-T) interface for local hardware management and debugging purposes. Id: 0900d8058080196c DN0947925

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