Fixed Wireless Featured Article

Airvana Finds Heavy Smartphone Signaling Load

By Gary Kim, Contributing Editor

Confirming separate research conducted by Bell Laboratories, engineers at Airvana (News - Alert) say an analysis of traffic on U.S. mobile networks shows that signaling intensity of smartphones is about eight times more intense than that of wireless-connected PCs.

 

The finding is important for several reasons. Mobile network congestion typically is thought of as an "end user bandwidth" problem. But Bell Labs (News - Alert) researchers earlier identified signaling issues as a key congestion issue for mobile networks.

 

The apparent problem network operators noticed was heavy congestion of the radio network when statistics showed that bearer traffic demand at the measured cell sites was not terribly heavy. Investigators discovered that signaling overhead was tying up radio ports, even in the absence of heavy bandwidth load.

 

Airvana engineers concur. Airvana engineers comparing data use profiles found that for a given volume of data transmitted, one smartphone typically generates eight times the network signaling load of a USB modem-equipped laptop.

 

Although smartphones may only account for a minority percentage of all devices on operator networks today, they are always on, moving between cell sites and continually ‘polling’ the network. As a result, smartphones are already responsible for the majority—two to three times as much as laptops—of the total signaling activity.

 

The reason that is important is that radio port capacity is consumed bys signaling overhead and bandwidth. So engineering just for bandwidth consumption might not improve performance as much as predicted.

 

Airvana has a huge interest in mobile offload using femtocells, so it is not surprising that the firm suggests this signaling load multiplier effect from smartphones shows the value of mobile broadband offload. But the problem is real enough.

 

“Conventional wisdom has been that data traffic produced by laptops equipped with mobile broadband was the culprit when looking at the impact on the network,” says David Nowicki (News - Alert), Airvana VP.

 

“The industry is just now beginning to understand the real impact of smartphones on network performance and we’re finding that their effect is distinctly out of proportion to the amount of data they transmit and receive," he says. "It’s now estimated that nearly 60 percent of all mobile data traffic originates indoors."

 

Global annual shipments of smartphone handsets are projected to increase from nearly 200 million in 2009 to 450 million in 2013, according to market research firm iSuppli Corp.

 

AT&T recently reported that smartphone penetration in their postpaid subscriber base has doubled to 36 percent and Verizon (News - Alert) reported that 40 percent of their handsets sold in the second quarter of 2009 were smartphones.

 

Of course, mobile offload might also be a revenue driver for some fixed network providers, and a key value provider for fixed broadband connections, even when ancillary revenue is relatively low.

Gary Kim (News - Alert) is a contributing editor for TMCnet. To read more of Gary’s articles, please visit his columnist page.

Edited by Stefania Viscusi