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WiMAX CID vs SFID-basic difference between CID and SFID in WiMAX

Th This page WiMAX CID vs SFID describes basic difference between CID and SFID parameters used in WiMAX system.

Service flows are a key feature of the 802.16 wimax standard. A service flow represents a unidirectional data flow. Transmitting bi-directional traffic requires that two service flows need be defined viz. one for the uplink, and another for the downlink. These service flows can have different QoS settings. Refer wimax QoS page for more details. The wimax base station allows multiple service flows to be configured for each subscriber station in a sector. This allows network service providers to offer different services and segregate traffic flows having different QoS requirements.

Data packets are forwarded by the base station based on classification rules. Classification rules require examining each packet for pattern matches such as destination address, source address or VLAN tag. All classification is defined at the wimax base station and the classification parameters are downloaded to the subscriber.

BS manufacturers usually provide screen for addition and deletion of service flow configuration. CS specification follows 802.3. There will be provision to set SFID for downlink and uplink with SS MAC ID setting.

A service flow in wimax is partially characterized by the following attributes:

1. A 32-bit Service Flow ID (SFID) is assigned to all existing service flows. The SFID serves as the principal identifier for the Service Flow and has an associated direction.

2. A 16-bit Connection ID (CID) is associated with each active SFID (connection active).

3. A set of QoS parameters specifying the required resources. The principal resource is bandwidth, but the specification may also include latency requirements.

4. A set of QoS parameters defining the level of service being provided.

Service flows are defined and stored in the base station. For each service flow to be established, the base station sends a setup message to the subscriber station specifying the required set of QoS parameters. The subscriber station responds to each request by accepting or rejecting the setup message. A service flow may be pre-provisioned or can be dynamically created and deleted without service outage. This is useful for supporting multiple subscribers in a single sector. New subscribers can be added and existing subscribers can be removed or have service levels modified. Setup messages are sent by the base station following any subscriber station power-cycle, loss and recovery of the wireless link to a subscriber station or any service flow add/delete operation at the wimax base station.


wimax SFID vs CID success
Fig-1 event log or network log in wimax system

Figure-1 above mentions event log captured by wimax compliant base station showing "service flow creation success" between Base Station(BS) and Subscriber Station(SS). There are two SFIDs each having unique CID. This refers to uplink and downlink connection.


WiMAX CID Table

CID Value Description
Initial Ranging 0x0000 Used by SS and BS during initial ranging procedure
Basic CID 0x0001-m The same value is assigned to both downlink and uplink connection
Primary management CID m+1 to 2m The same value is assigned to both downlink and uplink connection
Transport CIDs and secondary management CIDs 2m+1 to 0xFEFE For the secondary management connection, The same value is assigned to both downlink and uplink connection
Broadcast CID 0xFFFF Used for broadcast information which is transmitted on the downlink to all the SSs

What is Difference between

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Difference between SC-FDMA and OFDM
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Difference between TDD and FDD
Difference between 802.11 standards viz.11-a,11-b,11-g and 11-n
Bluetooth vs zigbee
Bluetooth vs zigbee
wibro vs mobile wimax
Microcontroller vs microprocessor
FDMA vs TDMA vs CDMA
FDM vs TDM
CDMA vs GSM
OFDM vs OFDMA
wimax vs lte

Links to WiMAX MAC Layer resources

REG REQ and REG RSP
SBC REQ and SBC RSP
DSA REQ and DSA RSP
UCD,UIUC,DCD,DIUC
DLMAP and ULMAP
WiMAX Ranging Procedure
WiMAX Bandwidth Request procedure
WiMAX Network Entry Procedure
WiMAX CID vs SFID
WiMAX FCH header format
WiMAX TLV Format basics
WiMAX Timers
WiMAX Network Interface types
WiMAX QoS Classes

               

RF and Wireless Terminologies


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