Smartphones, data hogs causing wireless network capacity crunch

Flat-rate plans also a key cause of wireless network data deluge

Two-thirds of wireless operators say their networks are suffering due to surging data traffic. The problems are inter-related, and operators are applying a range of technical and tariff changes to cope.

Two-thirds of wireless carriers say their networks are suffering due to the surge in data traffic. They're racing to apply a wide range of technical and tariff changes to cope with the problem, and with the growing customer dissatisfaction, according to a new global survey of network operations staff.

Overall, 20% of respondents say heavy data traffic causes "severe overload at specific times." Forty-three percent say network congestion is in "specific geographic areas." About 50% say capacity demand is intermittent and varies by time of day, but about 40% report that data demand is rising for all customers. About the same percentage (and characteristically operators in the Americas) say that "bandwidth hogs" -- a subscriber whose data traffic usage can consume much or even most of a given cell site's capacity -- are a major contributor to the capacity crunch.

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The survey was done by Telesperience, a U.K.-based telecommunications analyst company whose focus is on improving operational efficiency of service providers. The study was sponsored by Amdocs, a company that offers business and operational support systems, among other products, to network operators. 

For this survey, Telesperience used an approach it calls the "expert sample." The survey is based on only about 30 participants, but these were carefully chosen for their roles, knowledge and expertise in cellular wireless network operations, management and planning. A PDF file of the full report is available online  

The survey only skims the surface of the full depth of the considerable technical challenges facing wireless operators as they deal with soaring data demand on networks that were originally designed for voice calls. Cellular networks today are a mix of technologies, and for the past few years, operators have been investing in 3G network upgrades to add more capacity at cell sites.

Pie chart of survey results

The coming switch to LTE will provide a lot more bandwidth, but phasing it in will take time and money. MetroPCS deployed the first LTE network in Las Vegas in September.  

 The network experts identified several reasons for the surging data growth, but they vary in importance in different regions.

Overall, these respondents ranked smartphones as being the biggest contributor to the data crunch (4.06 of 5.0 points). Second was flat-rate (or unlimited) data plans, at 3.47, closely followed by bandwidth hogs, at 3.29, and laptops with mobile broadband at 3.22.

American operators all blamed the first two as the main culprits. By contrast, the tariff plans were the No. 1 cause in Europe; mobile broadband laptops were No. 1 in Asia. In the United States., AT&T last June announced it was ending unlimited data plan, in favor of two plans, one tailored for most current users, the other for users that routinely move lots of data. Both offer unlimited access to AT&T's nationwide Wi-Fi hotspot network.  Within days, Verizon executives hinted they would do the same

The survey offered several statements to identify the characteristics of what Telesperience calls the "capacity crunch." Just under 55% agreed that "peak capacity demand is related to service usage." Forty percent blame "bandwidth hogs" for "consuming a larger proportion of capacity."

Demand varies: about 50% of the sample agree that "capacity demand is intermittent and varies by time of day;" while about 30% said "peak capacity demand is localized to specific macrocells." Roughly 10% report that "peak capacity demand is unpredictable, but the study doesn't indicate if the unpredictability is increasing. Another 40% of the sample report that "demand for capacity is rising across all customers."

The impact of the data crunch is causing serious problems, but again the relative severity varies with the region. Telesperience asked the respondents to rank the "impacts of the data crunch." Overall, the most serious impact (4.94 out of 6), was the negative effect on customers' experience of data services. Second, was "more customers are making complaints about service quality" (4.11 of 6), followed by "driving up churn" -- subscribers abandoning one carrier for another (3.38 of 6).

In fourth place, with 3.31 of 6, was increased difficulty by operators in complying with the terms of the service level agreements for their business customers.

But American operators as a group ranked "driving up churn" as the lead impact.

To address the soaring data demand, the vast majority of experts in this survey say the key strategy is to expand their network's capacity, ranked at 4.56 on a "most useful strategy" scale of 6. Trailing well behind in usefulness were several others: off-loading, presumably shifting data traffic to Wi-Fi or some other wireless network, at 2.72; data or application optimization, to make both more efficient, at 2.67; pricing changes, such as tiered plans, at 2.65; and finally "traffic shaping," at 2.5.

One not very surprising finding is that individual cell sites and the backhaul connection from those sites are, separately, considered by far to be the two main data bottlenecks.

Addressing either one is a complex and costly process. Nearly every respondent, 97%, said they intend to deploy Ethernet as the main backhaul technology. A little over 15% of all respondents say they've already rolled it out; another nearly 35% are deploying Ethernet to more than 10% of their cell sites. Almost 25% say they will deploy Ethernet to more than 10% of cell sites during the next two to four years.

American network operators "were the least advanced" in Ethernet deployment plans, according to the report.

The Ethernet deployment faces significant technology challenges. Overall, respondents said they two biggest ones are end-to-end quality of service design for the network (about 58% identified this one); about 50% said the biggest challenge was capacity planning alignment between cell site transmission and RF.

One pressing issue, according to Telesperience, is the gap between the growth in capacity demand on one hand, and data services revenues on the other. Lagging or sagging revenues in the face of high demand becomes a "matter of concern when considering extra investment" in attack the crunch, according to the study.

John Cox covers wireless networking and mobile computing for Network World.

Twitter: http://twitter.com/johnwcoxnww

Email: john_cox@nww.com

Blog RSS feed: http://www.networkworld.com/community/blog/2989/feed

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