WiFi offloading, cell-phone batteries and dual-band access

Cell phones were originally designed for voice communications over the public cellular networks. Over time, Bluetooth wireless connectivity was added ...

More evidence that cellular and WiFi are complementary, not competitive, technologies.

By Scott Thompson, Oberon

Cell phones were originally designed for voice communications over the public cellular networks. Over time, Bluetooth wireless connectivity was added for convenience and connectivity to accessories. More recently WiFi has been integrated into some phones, and into most smartphones. The problem with WiFi is that the protocol itself was envisioned by the IEEE 802.11 wireless LAN architects as a convenient wireless replacement for cables in an Ethernet network, wherein the WiFi semiconductors could be powered by the PC's power supply or a laptop computer's large battery. Power efficiency was not a primary factor in the original WiFi architecture. So when WiFi chips designed for laptops are integrated into cell phones or smartphones they tend to draw an undesirable amount of power from the phone's small battery.

A report from UBM TechInsights looks at the progress of integration of WiFi into cell phones. While Bluetooth had achieved 100-percent adoption into handsets by 2010, WiFi had previously lagged. Since 2008, however, WiFi integration experienced explosive growth, and by 2010 had achieved a 92-percent adoption rate. This was largely fostered by the use of single-chip solutions (integrating WiFi and Bluetooth), which achieved 62-percent adoption by 2010. Although the availability of WiFi in standard handsets is still limited, the fastest growing segment of phones, the smartphones, all have WiFi integrated into them. With a smartphone, when WiFi is enabled there is a noticeable impact on battery life. Handset manufacturers and chipset designers have spent an enormous amount of design effort on conserving battery life while maintaining robust cellular communications utility of the phone. WiFi, on the other hand, has been an afterthought in handsets.

The current limitations of WiFi embedded into cell phones and smartphones will become more evident now as the cell-phone companies permit more mobile traffic to be unloaded onto available WiFi networks. The cell-phone companies recognize an impending deficit in available cellular spectrum. Spectrum availability is projected to cross a critical threshold at the end of 2012 according to a recent technical paper from the FCC, due to increased Web, data and video traffic. In order for their networks to continue to provide spectrum for essential voice communications, the cellular companies will more freely permit the mobile Web, data and video traffic to be unloaded onto public or private WiFi networks where available. And where will these WiFi networks be available? Homes, offices and public spaces. One study indicates that 62 percent of Internet-connected households have WiFi, and a growing number of businesses, schools, hospitals, government buildings and public spaces have a wireless LAN available. From the standpoint of spectrum conservation, throughput and availability, it behooves everyone to offload some of the traffic to available WiFi networks.

The aforementioned trends to increase WiFi usage, and limitations of WiFi in smartphones, have not gone unnoticed by the chipset manufacturers. In fact, the recent acquisition of leading wireless LAN chipset manufacturer Atheros by leading cellular chipset manufacturer Qualcomm, is positive affirmation of the need for the wireless LAN and cellular technologies to coexist and complement one another. As stated by Dr. Paul E. Jacobs, chairman and chief executive officer of Qualcomm, "It is Qualcomm's strategy to continually integrate additional technologies into mobile devices to make them the primary way that people communicate, compute and access content. This acquisition is a natural extension of that strategy into other types of devices. The combination of Qualcomm and Atheros is intended to accelerate this opportunity by utilizing best-in-class products for communications, computing and consumer electronics."

From this statement, one would strongly suspect that the Atheros WiFi chipset technology is going to be more thoroughly integrated into the handset, especially with regard to conservation of battery power and improved mobile performance. I suspect that in the near future, smartphones and tablet computers will have "always-on" WiFi capability, without as noticeable an impact on battery life. Additionally, Atheros has been a leader in integrated 2.4-GHz and 5-GHz multiple-input multiple-output (MIMO) WiFi chipsets, exploiting the 500 MHz of bandwidth available at 5 GHz versus the 80 MHz of bandwidth available at 2.4 GHz. So, although smartphones possess 2.4-GHZ WiFi at this time, very soon they will possess both 2.4- and 5-GHz WiFi.

As I have indicated previously, wireless networking is not a matter of cellular or WiFi; it is both technologies acting in concert. And from the standpoint of building the wireless infrastructure, the designer needs to be cognizant of the fact that handsets, mobile computers and other devices, imminently, will anticipate the availability of a robust, mission-critical cellular network and dual-band WiFi wireless LAN.

Scott Thompson is president of Oberon Inc. (www.oberonwireless.com).


Researchers predict significant mobile-VoIP growth

Reports recently issued by two market-research organizations both predict that the use of mobile Voice over Internet Protocol (mobile VoIP) will climb through the year 2015. One of the researchers, In-Stat (www.instat.com), explains, "Mobile VoIP is an extension of VoIP that allows for IP-based calls to be made from a mobile handset. Voice traffic travels over the available broadband connection, whether that connection is 3G, EDGE, WiFi or GPRS. Like fixed VoIP, mobile VoIP is being adopted in both the consumer and business segments, but has only recently begun to be implemented in the business environment."

In-Stat focuses on business use of mobile VoIP in its research report entitled "The Business of Mobile VoIP: IP Voice Communications in the Enterprise." Within the report it indicates that growth rates are strong and by the end of the forecast period in 2015, users will have grown to nearly 83 million lines or seats.

In-Stat senior analyst Amy Cravens says, "There are several reasons that adoption of mobile VoIP makes sense. Some of these include the ability to take the desktop phone experience with you, the ability to utilize the benefits of IP-based communication features, a cheaper international long-distance cost, an easy implementation path, and better indoor coverage where cell-phone reception has historically been poor."

In-Stat's research into the business mobile-VoIP market turned up the following points.

  • Business mobile VoIP users will increase tenfold over the next five years.
  • IP-PBX users will account for the majority of business mobile VoIP use.
  • Mobile operators are increasingly embracing mobile VoIP as they realize that demand for these offerings is not subsiding.
  • Hotspots open the potential for using VoIP over WiFi as more of a mobile service rather than a residential or business service.

Juniper Research (www.juniperresearch.com) also recently examined mobile VoIP, from the standpoint of the opportunities and challenges it presents to mobile carriers. In its report entitled "Mobile Voice Strategies - mVoIP Opportunities and Business Models, 2010-2015," the researcher found that the number of mobile VoIP minutes carried annually on 3G and 4G networks will rise from 15 billion minutes in 2010 to 470.6 billion by 2015. Juniper says that mobile VoIP traffic will rise steadily in all regions for the forecast period but particularly in developed markets due to the increasing availability of 3G networks.

Senior analyst Anthony Cox says, "There are several flavors of mobile VoIP. WiFi mobile VoIP is potentially the most damaging of all VoIP traffic as it bypasses the mobile networks altogether. We forecast that mobile VoIP over WiFi will cost operators $5 billion globally by 2015."

According to Juniper, other options for mobile VoIP carriage are via carrier alliances with mobile VoIP providers, or through an app downloaded to a handset or smartphone. Other findings of Juniper's research include the following.

  • Competitive and regulatory pressure will mean that traditional operators in developed markets will increasingly "bury the hatchet" and forge partnerships with VoIP providers.
  • Operator revenues from circuit-switched voice will continue to diminish over the five-year period, although the rate of decline will not accelerate.
  • The market opportunity for high-definition voice and advertising-based mobile voice services will be limited for the foreseeable future.

The researcher points out that operator sentiment over mobile VoIP varies. Cox notes, "Even though a major operator, 3UK, touts the benefits of mobile VoIP, it will take some time for many operators, particularly in emerging markets, to accept it, since it represents loss of control over their own networks."

-Patrick McLaughlin

More CIM Articles
Past CIM Issues

More in Wireless/5G