Clear Voice over Wi-Fi
Overcoming Wi-Fi Challenges Facing Digital Voice in the Home
Executive Summary
For consumers, Fixed/Mobile Convergence (FMC) means a world where integrated voice and data services are available everywhere through a single mobile handset that replaces disjoint cellular and landline telephones. For carriers, FMC represents a lucrative opportunity to leverage inexpensive technologies to offload increasingly-rich multimedia traffic from costly licensed network infrastructures. Broadband operators everywhere are interested in FMC to broaden the footprint of their services and infrastructure at a relatively low cost, augment coverage into buildings and increase subscriber “stickiness.”
Worldwide FMC revenue is poised to explode, with estimates reaching $28 billion and 92 million subscribers by 2011. To successfully tap this market, carriers will need to provide ubiquitous, reliable, cost-effective wireless coverage.
However FMC presents some new challenges for operators who have traditionally enjoyed control over voice connections on an end-to-end basis (see Figure on previous page). New dual-mode phones supporting both Wi-Fi and cellular technologies disable this control in the home where conventional Wi-Fi can wreak havoc due to interference and quality of service issues. Moreover, broadband operators are challenged to manage this last 100 feet. Existing voice services offered today over cellular, broadband VoIP and traditional POTs are all managed on and end-to-end basis. But with FMC there is no good way to gain visibility into or control over Wi-Fi connections in the home using conventional consumer-grade Wi-Fi. As a result, service quality can’t be guaranteed.
Broadband operators around the world are preoccupied with delivering new multimedia services -- the so-called triple or quad-play -- over residential broadband connections. While data was the initial driver for broadband, IPTV and voice are the new focus. This requires developing a reliable infrastructure to support all traffic types simultaneously. But inside the home, wires, despite their reliability, simply won’t cut it.
In particular, Wi-Fi has become the de-facto network for best-effort data delivery inside private residences, where cellular coverage is notoriously weak and costly to improve. Wi-Fi has great potential to enable converged service delivery inside the home with greater ubiquity, at lower cost, than licensed cellular -- IF Wi-Fi can be made sufficiently robust and reliable to carry paid voice services. However, two-way, interactive voice conversations are extremely vulnerable to delay and interference. For voice to work over Wi-Fi, wireless systems must be able to adapt in just milliseconds to changes in the radio frequency (RF) environment. Presenting a stronger, more reliable Wi-Fi link to voice handsets is critically important to overcome low or fluctuating signal strength that degrades voice quality and saps precious battery.
By maximizing transmit signal strength and receiver sensitivity, voice handsets can send the same information in shorter times, at lower power. This can be accomplished by using smart Wi-Fi antennas to narrowly direct signal towards each voice handset, reducing retransmissions, extending battery life, and improving user satisfaction.
