Backgrounder: Wi-Fi® Quality of Service Features Enable The Connected World
April 4, 2006 -- Wi-Fi: Enabling Connectivity in Consumer Electronics and Phones
Wi-Fi isn't just for PCs anymore. Now more than ever, Wi-Fi is an integral feature in new applications, from cellular phones to cameras, from digital entertainment systems to interactive video games. Whether a finance manager in a large enterprise wants to hold a high-quality VoIP conference call over his corporate WLAN, a teenager wants to compete against his friends on his gaming console, or a family wants to download high-definition video content via a digital media server, Wi-Fi technology is there --- providing the throughput and reliability these applications demand.
The Quality of Service (QoS) standard, IEEE 802.11e, outlines how Wi-Fi access points prioritize traffic in order to optimize the way shared network resources are allocated among different applications. Wi-Fi Multimedia (WMM) QoS is a key enabler of the transition from data-only use of Wi-Fi into voice, audio, and video applications. With an ample throughput rate and data prioritization provided by WMM, Wi-Fi is an excellent technology to handle voice calls, streaming high-definition video and interactive gaming applications under a wide variety of traffic and environmental conditions.
These important capabilities are enabling widespread adoption of Wi-Fi in non-PC devices. Analyst firm In-Stat predicts that consumer electronics and phones, now about 22 percent of the total market for Wi-Fi chipsets, will grow to comprise more than 60 percent of the market by 2009. Moreover, the overall Wi Fi market is expected to grow to nearly four times its current size during the same time frame (In-Stat, 2005) with consumer electronics and voice handsets the key drivers.
Industry Support for WMM
Because WMM is so critical to the user experience with digital home applications, the Digital Living Network Alliance (DLNA) recently announced that the latest version of its Home Networked Device Interoperability Guidelines includes a requirement that Wi-Fi enabled devices become Wi-Fi CERTIFIED™ for WMM if they support QoS. The addition of WMM to the guidelines augments the existing requirement that all Wi-Fi enabled devices become Wi-Fi CERTIFIED™ as part of DLNA interoperability certification.
The WMM program has seen a strong degree of participation from manufacturers of Wi-Fi devices such as access points, phones and consumer electronics. Certifications in the WMM program have risen steadily since the program's launch in September 2004, with an 81 percent quarterly increase during the fourth quarter of 2005 alone.
WMM: Prioritizing Different Applications for the Best User Experience
WMM is a set of features for Wi-Fi networks that improve the user experience for voice, video, and data applications. Based on a profile of the IEEE 802.11e standard, WMM prioritizes traffic demands from different applications and extends Wi-Fi's high quality end-user experience from data connectivity to voice, audio, and video applications under a wide variety of environment and traffic conditions.
WMM allows a network owner to set four priority levels, which correspond to different types of traffic:
-Voice - highest priority
-Video - second highest priority
-'Best effort' (applications like internet surfing and email) - third highest priority
-'Background' (applications which are not latency-sensitive, such as printing) - low priority
By prioritizing individual data streams according to the individual requirements of the application, WMM helps ensure that network traffic won't degrade the performance of a voice call or other highly sensitive application. With voice as the highest priority, WMM enables a single access point to support multiple concurrent VoIP calls with good quality and minimal latency effects such as delay or jitter.
WMM Power Save: Improving Power Consumption for Battery-Operated Devices
The WMM program includes an optional certification called WMM Power Save that leverages the WMM framework to increase low-power 'dozing' time and therefore increase battery life in small form factor devices.
In WMM Power Save, individual applications decide how often the client device needs to communicate with the access point and how long it can remain in a 'dozing' state. This gives battery-operated devices more flexibility in managing power consumption and a longer battery life. In a typical voice application, the Wi-Fi Alliance estimates battery life improvements ranging from 15 to 40 percent.
WMM and WMM Power Save are critical features as Wi-Fi technology proliferates in devices such as phones, gaming devices, and digital home media servers and clients. Device manufacturers and application developers can learn more by downloading two white papers:
-"WMM Power Save for Mobile and Portable Wi-Fi CERTIFIED™ Devices"
-"Wi-Fi CERTIFIED™ for WMM -- Support for Multimedia Applications with Quality of Service in Wi-Fi Networks"
Both papers are available for free download at www.wi-fi.org. Also available at the web site is a tool to find products which have been Wi-Fi CERTIFIED™ for WMM and WMM Power Save.
About the Wi-Fi Alliance
The Wi-Fi Alliance is a global, non-profit industry association of more than 250 member companies devoted to promoting the growth of wireless Local Area Networks (WLANs). With the aim of enhancing the user experience for mobile wireless devices, the Wi-Fi Alliance's testing and certification programs ensure the interoperability of WLAN products based on the IEEE 802.11 specification. Since the introduction of the Wi-Fi Alliance's certification program in March 2000, more than 2,500 products have been designated as Wi-Fi CERTIFIED™, encouraging the expanded use of Wi-Fi products and services across the consumer and enterprise markets.
Media contact: Edelman for Wi-Fi Alliance, Michael Diamond, firstname.lastname@example.org, +1 650-429-2772.
Wi-Fi®, Wi-Fi Alliance®, Wi-Fi CERTIFIED™, the Wi-Fi CERTIFIED™ logo, and the Wi-Fi logo are registered trademarks of the Wi-Fi Alliance. WMM , WPA, WPA2, Wi-Fi ZONE, and the Wi-Fi Alliance logo are trademarks of the Wi-Fi Alliance.