Voice over WiFi: it seems to be the coming thing, but is the technology ready?
via Flickr © Uncalno (CC BY 2.0)
Is hotspot and carrier WiFi technology now capable of providing ‘near ubiquitous’ voice and data connectivity? Will we soon see an outbreak of ‘WiFi first’ service offerings? Or will we just see WiFi increase its support role in hotspots and indoor dead spots over the coming few years?
Expect the argument to be loud and live at this year’s Mobile World Congress in early March when the great & the good of the global telecoms industry congregate to assess the state of the market and the threats and opportunities facing it.
A lot of WiFi announcements are likely being kept for early March, but we’re already seeing a few companies getting their retaliation in early.
One such is long-standing WiFi champion, Ruckus Wireless, which has introduced what it’s characterising as ‘Smart WiFi’ technology software innovations designed, it claims, to ease the introduction of IP-based voice calling over WiFi.
Ruckus points out that voice over Wi-Fi isn’t new. What’s dogged it is performance. All voice over IP is challenged by packet delay and jitter. VoIP works fine when it’s operating across an uncongested network; it’s when conditions become challenging - usually when too much data is contending for too little capacity - when ‘quality of experience’ suffers. It’s a problem on fixed IP networks and it’s an even bigger problem when WiFi adds more contention and delay at the far end.
Ruckus claims there’s a raft of measures that must be put into place to overcome the problems. Its ‘Smart WiFi innovations’ include “capacity-based client access control, Wi-Fi multimedia admission controls, directed roaming, and automatic packet flow heuristics.”
Here’s the claims...
Automatic QoS Heuristics
This is the ability to prioritize Wifi Calling traffic by looking at the Type of Service (ToS) bits set by the smartphone in the IP header, or by using automatic packet flow heuristics that examine the size and frequency of packets in any flow, encrypted or not.
Capacity-Based Client Access Control
If too many new devices attempt to connect to a given Wi-Fi access point (AP), already connected clients may experience service degradation. To get around that Ruckus can implement a capacity-based client access control algorithm to decline connection requests from new clients. Harsh but effective.
Using the 802.11v standard, directed roaming helps to ensure the overall quality of user experience by directing clients to another Wi-Fi access point when the existing one is congested or loses signal strength. It automatically provides a list of alternative access points and can request the client to move to a closer AP. This solves the problem of clients that stay connected or ‘sticky’ with a given AP, even if it no longer provides the best connection.
Wi-Fi Multimedia (WMM) Admission Control
This improves the performance for real time voice and video services by preventing oversubscription of bandwidth. Clients must request a specific amount of bandwidth before connecting and each AP takes into account network load and channel connections before allowing clients to connect.