ramSet (SFID and Active CID) FIGURE 6-19 The relationship between the QoS parameter sets [1] The main elements (or alternatively objects) of the legacy QoS framework and their attributes are shown in Table 6-7. Each object has a number of attributes. The optional attributes are denoted with brackets. A service flow may be associated with several PDUs, but a PDU is associated with exactly one service flow. The service flow is the central concept of the IEEE 802.16 MAC protocol. As mentioned earlier, there is a one-to-one mapping between admitted and active service flows identified by a 32-bit SFID and transport connections specified by a 16-bit CID. The information delivered to the MAC SAP includes the CID, identifying the transport connection over which the information is delivered. The service flow for the connection is mapped to the MAC transport connection identified by the CID. A Classifier Rule uniquely maps a packet to its transport connection. The Classifier Rule is associated with zero or one PHS Rule. When creating a PHS Rule, the associated Classifier Rule Index is used as a reference. A PHS Rule is associated with a single service flow. The PHS Rules associated with the same service flow are uniquely identified by their PHSI Table 6-7 The Main QoS Framework Elements are their Attributes [1] Object Attribute PHS Rule PHSI; PHSS;PHSF; PHSM; PHSV Classifier Rule Classification rule index; Classification criteria MAC PDU SFID; [Service class]; CID; Payload Service Flow SFID; Direction; [CID]; [ProvisionedQoSParamSet]; [AdmittedQoSParamSet]; [ActiveQoSParamSet] Transport Connection Connection ID; QoS parameter set Service Class Service class name; QoS parameter set 6.5 Quality of service (see Chapter 5). The Classifier Rule uniquely maps packets to its associated PHS Rule. The service class is an optional object that may be implemented at the BS and is referenced by an American Standard Code for Information Interchange (ASCII) code, which is intended for provisioning purposes. A service class is defined in 