Title New Adaptive Antenna Mac Section (substitute for Section 6.2.7.13)

This document purpose is to replace the entire section 6.2.7.13 of working document IEEE 802.16ab-01/01r1 named: “sub-11 Ghz support for advanced antenna technology”, in order to improve, clarify and provide a more accurate and specific text. The content of this new text is based on the same concept and architecture as the original section with modifications. The text reflects a consolidation of the two main contributors to MAC group in the field of Advanced Antenna Techniques. Purpose Replace the section 6.2.7.13 of working document IEEE 802.16ab-01/01r1 with an improved version. Notice This document has been prepared to assist IEEE 802.16. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. 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The contributor also acknowledges and accepts that this contribution may be made public by IEEE 802.16. 2001-09-06 IEEE 802.16.3c-01/81 1 Patent Policy and Procedures The contributor is familiar with the IEEE 802.16 Patent Policy and Procedures (Version 1.0) , including the statement “IEEE standards may include the known use of patent(s), including patent applications, if there is technical justification in the opinion of the standards-developing committee and provided the IEEE receives assurance from the patent holder that it will license applicants under reasonable terms and conditions for the purpose of implementing the standard.” Early disclosure to the Working Group of patent information that might be relevant to the standard is essential to reduce the possibility for delays in the development process and increase the likelihood that the draft publication will be approved for publication. Please notify the Chair as early as possible, in written or electronic form, of any patents (granted or under application) that may cover technology that is under consideration by or has been approved by IEEE 802.16. The Chair will disclose this notification via the IEEE 802.16 web site . 2001-09-06 IEEE 802.16.3c-01/81 2 New Adaptive Antenna MAC Section (substitute for section 6.2.7.13) General This document purpose is to replace the entire section 6.2.7.13 of working document IEEE 802.16ab-01/01r1 named: “sub-11 Ghz support for advanced antenna technology” from July 2001. It is proposed to substitute the entire section as a whole in order to improve, clarify and provide a more accurate and specific text. The content of this new text is based on the same concept and architecture as the original section with modifications. The main reason for the need to substitute the original text is the consolidation of two contributors to MAC group in the field of Advanced Antenna Techniques, to generate a single text that reflects both contributions [1] and [2]. In the IEEE 802.16.3 meeting #13 there were 2 contributions on the subject of Advanced Antenna Techniques [1], which was entered into the MAC document as section 6.2.7.13 and [2] which was submitted separately. By request of the TG3 MAC chair the contributors of these two documents had consolidated and generated a new document. We recommend using the following text (with properly adjusted subsection numbering), under section 6.2.7.13 of the sub-11 air interface document. Architectural overview Adaptive Antenna Arrays are elements of the BWA system that are used in conjunction with the PHY and MAC, to enhance the performance of the system. Adaptive Arrays can improve range and system capacity, and enable a system deployment in Non-Line-Of-Sight (NLOS) conditions. This section specifies the general architecture and the detailed mechanism in the MAC by which Adaptive Array enhancements can be added to the system. A general concept of “Adaptive Array Supportive” (AAS) system is defined in this chapter. The AAS system is capable of delivering the benefits of Adaptive Arrays and may also be compatible with non-AAS systems. The implementation of Adaptive Array in a BWA system requires both MAC and PHY to be AAS compliant, therefore it is assumed in this section that the AAS compliant MAC is operating in conjunction with an AAS compliant PHY. MAC services in AAS systems The use of Adaptive Array in the system shall not affect the definition of MAC services at the MAC service access point. When interfacing with higher layers, the AAS MAC appears exactly the same as non-AAS MAC does. Transition from non-AAS to AAS systems The architecture of AAS option provides a way to migrate from non-AAS system to AAS system by changing parts of the system first. During the migration phase the system may not be able to gain all AAS benefits, however as the mixture between AAS and non-AAS improves, the system capacity, range and inter-cell interference performance will significantly increase. The first change in the transition path should be to replace the base-station with an AAS base-station. By enabling coexistence of AAS and non-AAS subscriber stations in 2001-09-06 IEEE 802.16.3c-01/81 3 the same base-station service area, any mixture of AAS/non-AAS subscriber units can be deployed. At the end, if a system becomes full-AAS system, with all its components being AAS compatible (including base-station and all subscriber stations), it can be operated with the AAS option only, thus some of the MAC components that are used in non-AAS base-stations can be omitted. For example, the broadcast MAP used in non-AAS systems to indicate transmission scheduling can be omitted in a full-AAS system, since the AAS MAC uses private MAP messages designated to subscriber stations instead of the broadcast MAP. AAS framing It is envisioned that AAS is most beneficial for burst-mode PHYs, in particular systems using TDD as the duplexing scheme. During the migration from non-AAS to AAS, each part of the TDD time frame (UL part and DL part) is sub-divided into two logical parts. The first part is used for non-AAS subscriber stations, while the second part is used for AAS subscriber stations. For a non-AAS subscriber station, the TDD time frame appears like the expected frame, starting with the frame synchronization and control packets (MAP, UCD, DCD, etc.). The downlink burst modes and scheduling is received via DCD and DL-MAP, in the same way as in the nonAAS system. Thus a non-AAS subscriber station can be completely unaware of the fact that it is communicating with an AAS base-station. On the other hand, AAS subscriber stations use a different part of the downlink frame, starting immediately after the first part. The MAC sub-layer within these AAS stations has a special mechanism to schedule transmissions in the uplink and downlink, without using the regular broadcast MAP and DCD messages. The method by which an AAS subscriber station achieves time and frequency synchronization is dependent on the property of the underline AAS PHY, and is beyond the scope of this section. In order to be able to perform all MAC services, the AAS MAC should have some additional packets in the air interface time frame. These packets are transmitted during the fixed service slot within the AAS part of the frame, and are ignored by non-AAS subscriber stations. Figure 1 is an illustration of the logical division of the physical frames into non-AAS and AAS parts. For single carrier and OFDM systems, the division is based on time. For OFDMA systems, the division is based on both time and frequency, where the mapping is specified in the relevant sections on PHY. 2001-09-06 IEEE 802.16.3c-01/81 4 frame control Downlink AAS Downlink Uplink AAS uplink Flexible structure, according to DL-MAP Scheduled, according to UL-MAP MAP independent packets Scheduled, according to private MAPs TDD frame