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US 6,639,916 B1Granted
AAL receiving circuit and method of processing ATM cells
AssigneeNEC Corporation
InventorMayumi Wakizaka
Life of this patent
Estimating the term…
Abstract
Standard cells and AAL2 cells are processed by a single AAL terminating unit to reduce whole circuit scale of a radio communication system. An AAL identifying unit 3 determines whether an ATM cell is a standard cell or an AAL2 cell. When the ATM cell is a standard cell, the cell is transferred to the AAL terminating unit 7 as it is when the ATM cell is an AAL2 cell, the cell is assembled and to produce a plurality of ATM cells each of which corresponds to one of the short cells in the AAL2 cell and transferred to the unit 7. The unit 7 determines an AAL type of the ATM cell and processes then according to the AAL type.
Claims17
An AAL (ATM Adaptation Layer) receiving circuit which receives an ATM (Asynchronous Transmissions Mode) cell, comprising:
- an AAL identifying unit which identifies an AAL type of the ATM cell based on a value of a VCI (Virtual Channel Identifier) included in the ATM cell;
- a standard cell interchanging unit which receives the ATM cell and transfers the ATM cell with no change when the ATM cell is determined as a standard cell at the AAL identifying unit;
- an AAL2 (AAL Type 2) assembling unit which receives the ATM cell, divides the ATM cell into a plurality of short cells , appends a header of the ATM cell to each of the divided ATM cells, converts each of the header appended divided ATM cells into a form of the standard cell, and transfers each of the converted cells as an ATM cell, when the ATM cell is determined as an AAL2 cell;
- a cell multiplexer which multiplexes the ATM cells which are transferred from the standard cell interchanging unit and the AAL2 assembling unit, and transfers said multiplexed ATM cells to a common ATM bus;
- and
- at least one AAL terminating unit connected to the common ATM bus, said AAL terminating unit determining the AAL type of the ATM cell which is transferred from the common ATM bus and processing the ATM cell according to the determined AAL type.
3 more elements
An AAL (ATM Adaptation Layer) receiving circuit which receives an ATM (Asynchronous Transmissions Mode) cell comprising:
- an AAL identifying unit which identifies an AAL type of the ATM cell based on a value of a VCI (Virtual Channel Identifier) included in the ATM cell;
- a standard cell interchanging unit which receives the ATM cell and transfers the ATM cell with no change, when the ATM cell is determined as a standard cell at the AAL identifying unit;
- an AAL2 (AAL Type 2) assembling unit which receives the ATM cell, divides the ATM cell into a plurality of short cells, appends a header of the ATM cell to each of the divided ATM cells, converts each of the header appended divided ATM cells into a form of the standard cell, and transfers each of the converted cells as an ATM cell when the ATM cell is determined as an AAL2 cell;
- a cell multiplexer which multiplexes the ATM cells which are transferred from the standard cell interchanging unit and the AAL2 assembling unit, and which transfers them to a common ATM bus;
- a cell distributing unit which determines the AAL type of the ATM cell which is transferred from the cell multiplexer and transfers the ATM cell with processing according to the determined AAL type;
- and
- at least one AAL terminating unit which processes the ATM cell from the cell distributing unit according to the determined AAL type.
4 more elements
A method of AAL (ATM Adaptation Layer) processing of an ATM (Asynchronous Transmissions Mode) cell comprising the steps of:
- identifying an AAL type of a received ATM cell based on a value of a VCI (Virtual Channel Identifier) of the ATM cell;
- dividing the ATM cell into a plurality of short cells, appending a header of the ATM cell to the short cells, and converting each of the header appended divided ATM cells into the same form as a standard ATM cell, only when the ATM cell is determined as an AAL2 (AAL Type 2) cell;
- multiplexing standard ATM cells and the ATM cells which are obtained by the above conversion, and transferring the multiplexed cells to a common ATM bus;
- and
- referring to an AAL type of the ATM cell from the common ATM bus, processing the ATM cell according to predetermined definition which corresponds to the standard cell when the ATM cell is determined as a standard cell;
- determining a destination of the ATM cell by referring to a CID (Channel Identifier) of the ATM cell and processing the ATM cell according to predetermined definition which corresponds to the AAL2 cell when the ATM cell is determined as a AAL2 cell.
3 more elements
A method of AAL (ATM Adaptation Layer) processing of an ATM (Asynchronous Transmissions Mode) cell comprising the steps of:
- identifying an AAL type of the ATM cell based on a value of a VCI (Virtual Channel Identifier) of the ATM cell;
- dividing the ATM cell into a plurality of short cells, appending a header of the ATM cell to the short cells, and converting the header appended divided ATM cells into the same form as a standard ATM cell only when the ATM cell is determined as an AAL2 (AAL Type 2) cell;
- multiplexing standard ATM cells and the ATM cells which are obtained by the above conversion, and transferring the multiplexed cells to a common ATM bus;
- and
- determining a destination of the ATM cell from a VPI/VCI (Virtual Path Identifier and Virtual Channel Identifier) in a header of the ATM cell and transferring the ATM cell to a communication network which corresponds to the destination when the ATM cell is determined as a standard cell, and determining a destination of the ATM cell by referring to a CID (Channel Identifier) of the ATM cell and transferring the ATM cell to a communication network which corresponds to the destination when the ATM cell is determined as an AAL2 cell;
- and
- processing, at the communication network, the ATM cell according to the AAL type of the ATM cell.
4 more elements
A receiving circuit which receives a packet, comprising:
- a determining unit which determines whether the received packet has a first type defined by a standard structure or a second type defined by a structure including multiple messages each of which is to be sent in a packet;
- a standard packet interchanging unit which receives the packet and transfers the packet with no change when the packet is determined as a packet of the first type at the determining unit;
- an assembling unit which is operable in response to the second type of the received packet and which receives the packet, divides the packet for each messages in the packet, appends a header of the packet to each of the divided messages, converts the header appended divided messages into a form of an individual packet, and transfers the individual packet as a packet;
- a
- packet multiplexer which multiplexes the packets transferred from the standard packet interchanging unit and the assembling unit, and which transfers the multiplexed packets to a common bus;
- and
- at least one terminating unit which determines either one of the first and the second types transferred from the common bus and which processes the packet according to the determined type of the packet.
4 more elements
A method of receiving a packet, comprising the steps of:
- (a) determining whether the received packet has a first type defined by a standard structure or a second type defined by a structure including multiple messages each of which is to be sent in a packet;
- (b) receiving the packet and transferring the packet with no change when the packet is determined as a packet of the first type;
- (c) receiving the packet, dividing the packet for each messages in the packet, appending a header of the packet to each of the divided messages, converting the header appended packets into a form of individual packets, and transferring the individual packets as a packet, when the packet is determined a packet of the second type;
- (d) multiplexing the packets which are formed by (b) and (c), and transferring the packets;
- and
- (e) determining either one of the first and the second types and processing the packet according to the determined type.
3 more elements
Dependencies are inferred from the claim text.