IEEE 802.11ad Defining the Next Generation Multi-Gbps WiFi

IEEE 802.11ad Defining the Next Generation Multi-Gbps WiFi

This full text paper was peer reviewed at the direction of IEEE Communications Society subject matter experts for publication in the IEEE CCNC 2010 proceedings

evaluation methodology, and channel models. An initial proposal for a selection procedure in [12] describes a “call for complete proposals” procedure. A proposal is considered III. VERY HIGH THROUGHPUT STUDY GROUP complete if it addresses all the functional requirements and

The VHT SG began in May 2007. Initial presentations evaluation methodology requirements. In [12], the expectation highlighted the benefits of advanced technology in microwave is that the task group documents will be complete by January 2010 and presentation of complete proposals will occur in May bands. However, to address single link data rates in the giga-bit per second range, the group began investigating 2010. Group AD (TGad) began the process of developing a 60 GHz amendment to 802.11.

opportunities in the 60 GHz ISM band [7]. This led to the development of a 60 GHz PAR [8]. The 60 GHz PAR outlined the scope of PHY and MAC modifications to the 802.11 standard. The primary requirement is that the amendment must enable a throughput of at least 1 Gbps at the top of the MAC. The use of the term throughput dictates that MAC efficiency must be addressed, not just an improvement to the PHY data rate. As described in Section I, several other organizations are also defining specifications for 60 GHz operation, particularly IEEE 802.15.3c. Two requirements in the PAR address distinct identity from other groups. The first is maintaining the 802.11 user experience. This means maintaining the network architecture of the 802.11 system, e.g. infrastructure basic

service set, extended service set, access point, station. This also implies reusing and maintaining backward compatibility to the 802.11 management plane, e.g. association, authentication, security, measurement, capability exchange, management information base (MIB). The other requirement addressing distinct identity is fast session transfer between PHY’s. A fast session transfer mechanism could provide seamless rate fall back between VHT and 802.11n for multi-band devices. Consumers will be provided their expected WLAN coverage from combo 60 GHz and 2.4 / 5 GHz devices. A great deal of discussion took place in VHT SG regarding coexistence with various other systems in the 60 GHz band. As such, the 60 GHz PAR has a requirement that the system will provide mechanisms that enable coexistence with other systems. In a parallel effort in VHT SG, usage models were discussed in order to set the framework for the type of applications that may be targeted by this next generation technology. The Wi-Fi Alliance presented a collection of usage models requiring higher throughput than available by current technology [10]. These included wireless display, in home distribution of HDTV and other content, rapid upload and download of large files to/from a server, backhaul traffic, campus / auditorium deployments, and manufacturing floor automation. The WFA report did not specify which band of operation would be better suited to which usage model. There was some discussion in the study group to identify which of the WFA usage models would be more suited to <6 GHz versus 60 GHz [11]. Short distance, single link applications requiring high data rates like uncompressed video and desktop storage

and display were associated solely with 60 GHz. However, other applications like lightly compressed video streaming around a home were mapped to <6 GHz.


TGad began in January 2009. The initial plans were highlighted to be the development of the following task group

documents: selection procedure, functional requirements, A. Functional Requirements The approved initial draft of the TGad Function Requirement document is [13]. Most of the requirements mirror those in the PAR; however there are three additional requirements. First, all devices are required to support a maximum PHY rate of at least 1 Gbps. Second, the amendment must provide a means of achieving 1 Gbps throughput at a range of at least 10m in some NLOS conditions. This mostly means that t