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IEEE Std 802.16-2001

LOCAL AND METROPOLITAN AREA NETWORKS—PART 16:

11.4.8.4.1 Errored parameter

The value of this parameter identifies the subtype of a requested service flow parameter in error in a rejected service flow request or Service Class Name expansion response. A Service Flow Error Parameter Set shall have exactly one Errored Parameter TLV within a given service flow encoding.

Type

Length

Value

Scope

 

 

 

 

[24/25].5.1

1

Service Flow Encoding Subtype in Error

DSx-RSP

 

 

 

DSx-ACK

 

 

 

 

11.4.8.4.2 Error code

This parameter indicates the status of the request. A non-zero value corresponds to the Confirmation Code as described in 11.4.12. A Service Flow Error Parameter Set shall have exactly one Error Code within a given service flow encoding.

Type

Length

Value

Scope

 

 

 

 

[24/25].5.2

1

Confirmation Code except OK (0)

DSx-RSP

 

 

 

DSx-ACK

 

 

 

 

A value of OK(0) indicates that the service flow request was successful. Since a Service Flow Error Parameter Set only applies to errored parameters, this value shall not be used.

11.4.8.4.3 Error message

This subtype is optional in a Service Flow Error Parameter Set. If present, it indicates a text string to be displayed on the SS console and/or log that further describes a rejected service flow request. A Service Flow Error Parameter Set may have zero or one Error Message subtypes within a given service flow encoding.

Type

Length

Value

Scope

 

 

 

 

[24/25].5.3

n

Zero-terminated string of ASCII characters.

DSx-RSP

 

 

 

DSx-ACK

 

 

 

 

NOTE—The length n includes the terminating zero.

11.4.8.5 QoS parameter set type

This parameter shall appear within every service flow encoding. It specifies the proper application of the QoS Parameter Set: to the Provisioned set, the Admitted set, and/or the Active set. When two QoS Parameter Sets are the same, a multibit value of this parameter may be used to apply the QoS parameters to more than one set. A single message may contain multiple QoS parameter sets in separate type 24/25 service flow encodings for the same service flow. This allows specification of the QoS Parameter Sets when their parameters are different. Bit 0 is the lsb of the Value field.

300

Copyright © 2002 IEEE. All rights reserved.

AIR INTERFACE FOR FIXED BROADBAND WIRELESS ACCESS SYSTEMS

IEEE Std 802.16-2001

For every service flow that is preprovisioned and for every provisioned service flow added after SS initialization, there shall be a service flow encoding that specifies a ProvisionedQoSParamSet. This service flow encoding, or other service flow encoding(s), may also specify an Admitted and/or Active set.

Type

Length

Value

Scope

 

 

 

 

[24/25].6

1

Bit 0: Provisioned Set

DSx-REQ

 

 

Bit 1: Admitted Set

DSx-RSP

 

 

Bit 2: Active Set

DSx-ACK

 

 

Bits 3-7: reserved

 

 

 

 

 

A BS shall handle a single update to each of the Active and Admitted QoS parameter sets. The ability to process multiple service flow Encodings that specify the same QoS parameter set is not required and is left as a vendor-specific function. If a DSA/DSC contains multiple updates to a single QoS parameter set and the vendor does not support such updates, then the BS shall reply with Confirmation Code 2 (reject-unrecognized-configuration-setting).

Table 141 lists values used in Dynamic Service Messages.

 

Table 141—Values used In Dynamic Service Messages

 

 

 

Value

 

Messages

 

 

 

001

 

Apply to Provisioned set only

 

 

 

011

 

Apply to Provisioned and Admitted set, and perform admission control

 

 

 

101

 

Apply to Provisioned and Active sets, perform admission control, and

 

activate this service flow

 

 

 

 

 

111

 

Apply to Provisioned, Admitted, and Active sets; perform admission control

 

and activate this service flow

 

 

 

 

 

000

 

Set Active and Admitted sets to Null

 

 

 

010

 

Perform admission control and apply to Admitted set

 

 

 

 

 

Check against Admitted set in separate service flow encoding, perform

100

 

admission control if needed, activate this service flow, and apply to Active

 

 

set

 

 

 

110

 

Perform admission control and activate this service flow, apply parameters to

 

both Admitted and Active sets

 

 

 

 

 

11.4.8.6 Traffic priority

The value of this parameter specifies the priority assigned to a service flow. Given two Service flows identical in all QoS parameters besides priority, the higher priority service flow should be given lower delay and higher buffering preference. For otherwise nonidentical service flows, the priority parameter should not take precedence over any conflicting service flow QoS parameter. The specific algorithm for enforcing this parameter is not mandated here.

Copyright © 2002 IEEE. All rights reserved.

301

IEEE Std 802.16-2001

LOCAL AND METROPOLITAN AREA NETWORKS—PART 16:

For uplink service flows, the BS should use this parameter when determining precedence in request service and grant generation, and the SS shall preferentially select contention Request opportunities for Priority Request CIDs based on this priority and its Request/Transmission Policy (see 11.4.8.12).

Type

Length

Value

Scope

 

 

 

 

[24/25].7

1

0 to 7 — Higher numbers indicate higher priority

DSx-REQ

 

 

 

DSx-RSP

 

 

 

DSx-ACK

 

 

 

 

NOTE—The default priority is 0.

11.4.8.7 Maximum sustained traffic rate

This parameter is the rate parameter Rate of a token-bucket-based rate limit for packets. Rate is expressed in bits per second and shall take into account all MAC PDUs of the service flow from the byte following the MAC header HCS to the end of the MAC PDU payload. The number of bytes forwarded (in bytes) is limited during any time interval T by Max(T), as described in the expression

Max(T) = T * (Rate / 8) + B,

(1)

where the parameter B (in units of bytes) is the Maximum Traffic Burst Configuration Setting (see 11.4.8.8).

NOTES

1—This parameter does not limit the instantaneous rate of the service flow.

2—The specific algorithm for enforcing this parameter is not mandated here. Any implementation which satisfies the above equation is conformant.

3—If this parameter is omitted or set to zero, then there is no explicitly enforced traffic rate maximum. This field specifies only a bound, not a guarantee that this rate is available.

The SS shall defer uplink packets that violate (1) and “rate shape” them to meet the expression, up to a limit as implemented by vendor buffering restrictions, or discard non-conforming packets.

The BS shall enforce expression (1) on all uplink data transmissions. The BS may consider unused grants in calculations involving this parameter. The BS may enforce this limit by any of the following methods: (a) discarding over-limit requests, (b) deferring (through zero-length grants) the grant until it is conforming to the allowed limit, or (c) discarding over-limit data packets. A BS shall report this condition to a policy module. If the BS is policing by discarding either packets or requests, the BS shall allow a margin of error between the SS and BS algorithms.

For a downlink service flow, this parameter is only applicable at the BS. The BS shall enforce expression (1) on all downlink data transmissions. The BS shall not forward downlink packets that violates (1) in any interval T. The BS should “rate shape” the downlink traffic by enqueuing packets arriving in excess of (1), and delay them until the expression can be met.

Type

Length

Value

Scope

 

 

 

 

[24/25].8

4

Rate (in bits per second)

DSx-REQ

 

 

 

DSx-RSP

 

 

 

DSx-ACK

 

 

 

 

302

Copyright © 2002 IEEE. All rights reserved.

AIR INTERFACE FOR FIXED BROADBAND WIRELESS ACCESS SYSTEMS

IEEE Std 802.16-2001

11.4.8.8 Maximum traffic burst

The value of this parameter specifies the token bucket size B (in bytes) for this service flow as described in expression (1). This value is calculated from the byte following the MAC header HCS to the end of the MAC PDU payload.

Type

Length

Value

Scope

 

 

 

 

[24/25].9

4

B (bytes)

DSx-REQ

 

 

 

DSx-RSP

 

 

 

DSx-ACK

 

 

 

 

NOTE—The specific algorithm for enforcing this parameter is not mandated here. Any implementation which satisfies the above equation is conformant.

11.4.8.9 Minimum reserved traffic rate

This parameter specifies the minimum rate, in bits per second, reserved for this service flow. The BS should be able to satisfy bandwidth requests for a service flow up to its Minimum Reserved Traffic Rate. If less bandwidth than its Minimum Reserved Traffic Rate is requested for a service flow, the BS may reallocate the excess reserved bandwidth for other purposes. The aggregate Minimum Reserved Traffic Rate of all service flows may exceed the amount of available bandwidth. The value of this parameter is calculated from the byte following the MAC header HCS to the end of the MAC PDU payload. If this parameter is omitted, then it defaults to a value of 0 bits per second (i.e., no bandwidth is reserved for the flow by default).

This field is only applicable at the BS and shall be enforced by the BS.

Type

Length

Value

Scope

 

 

 

 

[24/25].10

4

Rate (in bits per second)

DSx-REQ

 

 

 

DSx-RSP

 

 

 

DSx-ACK

 

 

 

 

NOTE—The specific algorithm for enforcing the value specified in this field is not mandated here.

11.4.8.10 Vendor-specific QoS parameters

This allows vendors to encode vendor-specific QoS parameters. The Vendor ID shall be the first TLV embedded inside Vendor-specific QoS Parameters. If the first TLV inside Vendor-specific QoS Parameters is not a Vendor ID, then the TLV shall be discarded (see 11.4.11).

Type

Length

Value

Scope

 

 

 

 

[24/25].43

n

 

DSx-REQ

 

 

 

DSx-RSP

 

 

 

DSx-ACK

 

 

 

 

Copyright © 2002 IEEE. All rights reserved.

303

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