Usually, the development of a new standard (or amendment of a standard) begins by identifying a specific application-niche. Competing standards often have significant overlap in their capabilities, and most technologies compete for spectrum space. Each of the standards discussed in this post has its own distinctive features (like key application, compatibility issues, maximum data rate, supporting company, etc.), but what they have in common is their goal to enable Gigabit per second and higher communications over distances of up to 10 meters .
Depending on what moment in time you examine (the history of these standards is a bit complicated), there have been four or five major players in the field of standardization of systems in the 60 GHz band, either concentrated on Wireless Local Area Networks (WLANs) or Wireless Local Personal Networks (WPANs).
The Task Group 3c (TG3c) of the IEEE 802.15.3 was one of the pioneers in considering the 60 GHz band. As the official website of the Task Group puts it :
“The IEEE 802.15.3 Task Group 3c (TG3c) was formed in March 2005. TG3c developed a millimeter-wave-based alternative physical layer (PHY) for the existing 802.15.3 Wireless Personal Area Network (WPAN) Standard 802.15.3-2003. This mmWave WPAN operates in the new and clear band including 57-64 GHz unlicensed band defined by FCC 47 CFR 15.255. In addition, the millimeter-wave WPAN supports high data rate at least 1 Gbps applications such as high speed internet access, streaming content download (video on demand, home theater, etc.). Very high data rates in excess of 2 Gbps in option is provided for simultaneous time dependent applications such as real time multiple HDTV video stream and wireless data bus for cable replacement.”
They call it a “millimeter-wave-based alternative PHY” because the wavelength of signals with a frequency of 60 GHz is in the order of millimeters. The standard IEEE 802.15.3c-2009 was published in September 2009.
Although allegedly there were initially some disputes when news of IEEE 802.11ad arose, they were quickly resolved when it became evident that they pursued different goals and were not a threat to each other. IEEE 802.15.3 has no compatibility with the IEEE 802.11 family of standards (Wi-Fi), and is exclusively a WPAN standard. Unlike the rest of the standards herein discussed, it does not seek to replace Wired Digital Interfaces (WDIs), so whatever success 802.15.3c has achieved is part of a different discussion. After a plenary session in Atlanta on November 2009, the task group was placed into hibernation, and it remains so .
WirelessHD (WiHD) was the first industrial consortium to develop a specification to transmit an uncompressed HDMI signal over a 60 GHz radio link , and their specification was available for adoption since January 2008. Originally, WiHD was conceived as an effort to develop a high speed option for the IEEE 802.15.3c standard . As stated in FAQs section of the official website of the consortium , it was “formed to develop a wireless HD digital interface in order to simplify HD audio and video (“A/V”) connectivity and content portability for consumers”. The leaders (or as they call themselves, Promoters) of the consortium are LG, Panasonic, Philips, Samsung, Silicon Image, Sony, and Toshiba, with many more companies as adopters of the standard.
The standard was developed from the ground up with the transmission of HD video and audio as its primary goal, without using a preexisting technology such as Wi-Fi that would not be optimized for these applications . What is more, WirelessHD, just like 802.15.3c is not compatible with Wi-Fi.
Some highlights of the standard are :
- Support for high data rates up to 10 – 28 Gbps, sufficient to transmit lossless HD video, multichannel audio, and data simultaneously.
- 2 channels of 192 KHz 2 channel LPCM.
- 5.1 channels of 24-bit 96 KHz multi-channel LPCM audio.
- 13.1 channels of 24-bit 192 KHz compressed Dolby TrueHD or DTS-HD audio.
The promise to would-be consumers is to get rid of bulky and uncomfortable cables (like HDMI cables) by providing them with seamless, wireless connectivity between digital source devices such as Blu-ray players, portable games, digital cameras, digital A/V players, personal computers (PCs and notebook PCs), portable media players and digital video recorders, and their HDTVs or other display devices, allowing users to quickly and easily share content between devices without the confusion of cables over distances of up to 10 meters (with no line-of-sight restrictions) .
Ecma International (which originally stood for European Computer Manufacturers Association) is “an industry association founded in 1961, dedicated to the standardization of Information and Communication Technology (ICT) and Consumer Electronics (CE)” . It is an international, private (membership-based), non-profit standards organization, and its publications can be freely copied by all interested parties without copyright restrictions. Ecma International takes pride in its “business-like” approach to standards based on its membership-based organization, because –they argue– it leads to better standards in less time thanks to a less bureaucratic process focused on achieving results by consensus .
The first edition of the ECMA-387 standard was approved in December, 2008. It “is a standard for a 60 GHz PHY, MAC and HDMI PAL for short range unlicensed communications providing high rate wireless personal area network (including point-to-point) transport for both bulk data transfer and multimedia streaming; addressing usages and applications such as high definition (uncompressed / lightly compressed) AV streaming, access point, wireless docking station, and short range sync-and-go.” . The standard defines 3 types of devices (A, B and C) depending on their level of performance, complexity and power consumption. Type A devices are considered high-end, and as such they achieve the highest data rates provided by the standard: 0.397-6.350 Gbps in a single channel. Also, type A devices are capable of dealing with severe multipath channels and support adaptive antenna arrays. Most importantly, devices of types A and B can further increase their data rate by factors of 2, 3 or 4 by bonding adjacent channels together, according to the 60 GHz band channel plan depicted in Figure 7. The applications envisioned for the links achievable with this standard are HD video streaming, fast file transfer between hand-held devices such as mobile phones and media kiosks or personal computers, and wireless docking stations. . A second edition of the standard was published in September 2010.
WiGig (IEEE 802.11ad)
The Task Group ad (TGad) of the 802.11 Working Group of the IEEE had their Project Authorization Request approved in December 2008. It was started with the objective “To define standardized modifications to both the 802.11 physical layers (PHY) and the 802.11 Medium Access Control Layer (MAC) to enable operation in the 60 GHz frequency band (typically 57-66 GHz) capable of very high throughput” .
The 802.11a/b/g/n versions of Wi-Fi all fail to provide Gbps data rates. The 802.11ac amendment had already achieved 1 Gbps by exploiting the 5 GHz band more effectively, but a truly meaningful extension of Wi-Fi is to come with IEEE 802.11ad, which enables data rates of up to 7 Gbps (more than 10 times the maximum rate of 802.11n) . In the words of Bruce Kraemer, chair of the IEEE 802.11 WLAN Working Group :
“IEEE 802.11 is undergoing a continuous process of refinement and innovation to address the evolving needs of the marketplace, and there is no better proof of that fact than IEEE 802.11ad. By migrating up to the next ISM band (60 GHz), we break ground on new spectrum for IEEE 802.11, enable an order of magnitude improvement in performance and enable usages that have never before been possible with existing IEEE 802.11 — namely wireless docking and streaming video.”
The Wireless Gigabit Alliance (WiGig Alliance) was formed in May 2009 by “technology leaders within the Consumer Electronics (CE), PC, semiconductor and handheld industries to address the need for faster, wireless connectivity between computing, communications and entertainment devices” .
Some of these leading companies are Broadcom Corporation, Cisco Systems Inc., Dell Inc., Intel Corporation, Microsoft Corporation, NEC Corporation, Nokia Corporation, Panasonic Corporation, Qualcomm Atheros, Samsung Electronics Co., Toshiba Corporation and Wilocity. Any company may participate in WiGig Alliance. Prospective members are required to sign a member’s agreement, which provides license rights for use of the WiGig specification . Their mission was to establish a unified specification for 60 GHz wireless technologies and drive a global ecosystem of easy-to-use, interoperable, multi-gigabit wireless products. In my opinion, interoperable is a key word here.
WiGig published their specification WiGig version 1.0 in May 2010, and version 1.1 in June 2011, delivering data rates of up to 7 Gbps, nearly 50 times faster than the highest 802.11n rate, while maintaining compatibility with existing Wi-Fi devices, although within a reduced range: the now familiar line-of-sight 10 m indoor range of 60 GHz technologies. This compatibility, however, provides the advantage that if the user walks outside the main room, the protocol seamlessly switches to one of the lower Wi-Fi bands that work at a much slower rate, but that do propagate through walls .
WiGig and TGad have cooperated extensively and share common goals, despite the very different nature of both organizations (IEEE being a formal Standards body, and WiGig an industry consortium). In cooperation with WiGig, the IEEE Std P802.11ad-2012 was developed and obtained final approval in October 2012. There are already hundreds of millions of IEEE 802.11 (Wi-Fi) products deployed worldwide, and WiGig is based on this standard. Some of the key features of the standard are :
- Support for data transmission rates up to 7 Gbps; all devices based on the WiGig specification will be capable of gigabit data transfer rates.
- Designed from the ground up to support low-power handheld devices such as cell phones, as well as high-performance devices such as computers; includes advanced power management.
- Based on IEEE 802.11; provides native Wi-Fi support and enables devices to transparently switch between 802.11 networks operating in any frequency band including 2.4 GHz, 5 GHz and 60 GHz.
- Support for beamforming, maximizing signal strength and enabling robust communication at distances beyond 10 meters.
- Advanced security using the Galois/Counter Mode of the AES encryption algorithm.
- Support for high-performance wireless implementations of HDMI, DisplayPort, USB and PCIe.
This relationship between WiGig and IEEE will be further explored in the next post.
As mentioned above, there were initial worries in the task group TG3c of the working group (WG) 802.15 when news broke of the plans of TGad for WG 802.11. In fact, during one of the first meetings of TGad in January 2009, one of the main topics was a presentation called “802.15.3c Coexistence Assurance Document presentation”. Once the certainty of coexistence was established, the IEEE 802.15.3c went back to its low profile status. As for ECMA-387, even after extensive research, I have been unable to find any devices that use the technology, or any company who has adopted the standard. This is despite the fact that a second edition of the standard was published in 2010. Both IEEE 802.15.3c and ECMA-387 are, in my opinion, part of a different discussion. The former perhaps because it was never intended to achieve the same goals as IEEE 802.11ad and WiHD have set out to achieve, while the latter appears to have failed to lure any adopters. Therefore, from this point on they will not be addressed anymore.
Both WiHD and WiGig are industry-led consortia. Among the reasons for using a consortium instead of a formal standardization organization are that generally they work faster, there is confidentiality among the companies involved (usually by means of non-disclosure agreements), and more possibilities to retain Intellectual Property (IP) rights . This is true both for WiHD and WiGig: the two of them are membership-based and produced their standards at rapid pace. The TG3c of WG IEEE 802.15 was founded in 2005 and it took until 2009 to have a standard ready. TGad of WH 802.11 was formed in December 2008 and the IEEE Std P802.11ad-2012 standard was published in October 2012, even when it assimilated most of the WiGig standard. It is then not hard to argue that industry consortia can work faster than formal standards organizations.
Hesser, Feilzer and de Vries  explain that sometimes, standards developed by a consortium are offered to a formal standardization organization at a later stage, and that the reasons for this may include giving the standards additional status, making them better known and ensuring its maintenance by the technical committee of the formal standards organization (since consortia may be dismantled at any given time). These reasons are well reflected in the words of Ali Sadri, President and Chairman of the WiGig Alliance when explaining the cooperation between WiGig and IEEE :
“Our members have worked closely with IEEE on developing the standard. We are excited to say that the WiGig MAC/PHY specification is completely aligned with the published 802.11ad standard. Gaining approval from a global standardization body gives WiGig Alliance additional international recognition and moves us one step closer to widespread industry adoption.”