As home networking, or more accurately “no new wires” home networking, enters its sophomore year, a significant trend is emerging. Home networking ingredient providers and system OEMs are coming to the realization that data communications is but one facet of in-home networks. It has become apparent that voice and video content will also be widely distributed within the home.
Unlike data transmission, voice and video depend more on reduced latency, accurate delivery and prioritization. Parameters for delivery of service need to be defined and implemented. In other words, Quality of Service (QoS) features need to be specified within the home networking protocols.
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Low latency is important because voice and video are intrinsically time-sensitive. By contrast, most data streams are asynchronous and are not high priority. Accurate delivery of voice and video signals is key because retransmission of lost packets of such signals is of no value. Therefore, the initial transmission needs to be robust and accurate. The complexity factor greatly increases with video content that typically has an accompanying audio track. The two streams need to be time-stamped to achieve synchronization.
Another aspect is that the network bandwidth capacity is limited. Therefore, if multiple signals need to be handled, the system needs to be able to prioritize time-sensitive communications.
The importance of QoS is becoming highlighted as service providers look at home networking solutions to extend the broadband pipe they are bringing into homes. These service providers hope to bring not just data into the home, but eventually voice and video as well. For service providers, applications such as Voice over Internet Protocol (VoIP) and streaming video suggest a definite revenue generation opportunity. Therefore, what is most important to them is that they qualify the home networking solution on the customer premises so that it can deliver the full value of the “fat pipe” into the home.
Service providers will increasingly implement QoS in their delivery mechanisms to the home. It is only reasonable that they demand that networks within the home also implement similar QoS procedures to maximize the user experience. Just as there will be multiple, competing communication streams that need to make use of the access network to the home, they are also expected to make use of the distribution network within the home. Remember that service providers are the primary customers for residential gateways, and they will demand QoS to handle the bundle of services they intend to deliver to the home.
There is already some formal movement to focus on and improve the QoS extensions in various home networking technologies. The HomePNA 2.0 specification has QoS provisions while HomePNA 1.0 had virtually none. Part of the reason for the desire for QoS is that while HomePNA 1.0 was rated at just 1 Mbps, HomePNA 2.0-compliant solutions are currently available at 10 Mbps. The increase in bandwidth capacity makes it more viable for carrying time-sensitive video streams and voice communications. This clearly implies there is a need for QoS.
Another example of QoS extensions is ongoing improvements to IEEE 802.11b, which specifies wireless data rates of 11 Mbps. Since IEEE 802.11 is primarily a data protocol standard, extensions need to be defined that address QoS requirements of transmitting voice and video. The so-called QoS and multimedia enhancements are being processed through the IEEE. Lucent, ShareWave and AT&T have presented their protocols, and have agreed to produce a joint submission. A technical requirements document is expected by the end of 2000, and final ratification may occur in early 2001. This will also be applicable to the IEEE 802.11a standard being developed for the 5 GHz frequency band.
Allied Business Intelligence believes that these are simply the first attempts to address the need for explicit QoS in home networking technologies. In time, other home networking technology backers will capitalize on existing QoS procedures, and/or develop more comprehensive QoS features. The communication environment in the home is diverse. Transmission algorithms need flexibility in order to deliver high-priority content in a robust fashion.
This trend will be accelerated as home networking evolves from being a network interface card (NIC) phenomenon, which plugs into PCs, to being embedded into residential gateways and consumer electronics products.
Allied Business Intelligence Inc is an Oyster Bay, NY-based technology research think tank specializing in communications and emerging technology markets. ABI publishes strategic research on the broadband, wireless, electronics, networking, energy and transportation industries. Details of these studies can be found at www.alliedworld.com. Or call 516-624-3113 for more info.