Smartphone Battery Life: The Impact of the Device Radio

Even with ongoing improvements in battery technology, many mobile phone users remain less than satisfied with the battery life of their devices. When a device cannot make it through a full day without needing to be recharged, this can result in a significant inconvenience for the mobile user.

It is common knowledge that a smartphone’s display consumes large amounts of energy and therefore has a significant impact on battery life. Less well-known is the “silent killer” of battery life: energy consumption by the device radio. We have found that for typical users, the radio can account for between one-third and two-thirds of battery use. What’s more, much of the radio activity draining the battery occurs when the user is not actively using the device. (This is in contrast to battery consumption by the screen, since the screen being on correlates strongly with active use). Many of the most popular applications continue to interact with the network to receive updates when the screen is off. These background interactions result in frequent device connections that cause the radio to remain in a higher energy state.

To illustrate the impact of connections and time connected on battery life, here is a plot of current draw in milliamps (mA) over time as a device connected to an actual LTE network: connection-chart1 The brief, smaller spikes are the result of the device synchronizing with the network, which occurs at intervals of about a second and a quarter. These smaller spikes have a short duration, so they do not have a significant effect on overall battery use.

The device connection is the large period of increased energy draw in the middle of the chart. We can clearly see that immediately prior to initiation of the network connection at approximately 2836 seconds, the average current draw is negligible. As soon as the connection is initiated, the current draw jumps up to more than 300 mA, and subsequently drops down to roughly 180 mA until the connection is dropped at 2852 seconds.

From this example we can see that the current draw when the device is connected averages about 200 mA, compared to about 4 mA when the device is not connected. This indicates that a device connection causes the battery to drain fifty times faster than it does in the idle state. Another way of looking at this is that one second of connection time is equivalent to fifty seconds in the “not connected”, or “standby” state. Our tests also show that time connected has a much stronger effect on battery drain than the number of device connections.

These results parallel those presented by Google as part of their Android L feature announcement at the Google I/O developers’ conference. They examined the battery impact of several scenarios in which a device wakes up from an idle state, involving the screen, the radio, and/or the CPU. Their research showed that for every second that a device is active, standby time is reduced by a full two minutes. This 120-1 ratio is consistent with our results, given that their tests included scenarios where the screen was on.

The significance of all of this is that device connections happen frequently during the day, most of them the result of background activity created by chatty mobile apps. To the degree that we can reduce the number and duration of device connections, we can both relieve signaling congestion in the network and extend device battery life. Our traffic optimization technology is able to do this without adversely impacting end-user experience.

Posted in Longer Battery Life, Mobile Technology, Network Congestion, Smartphone battery life, Traffic Optimization, Unnecessary Signaling | Tagged , , , | Leave a comment

Measuring Mobile Traffic Optimization: Connections and Time Connected

Signaling messages occur at a deep layer in the network, and therefore are not directly observable. This means that we must rely on other metrics to determine the efficacy of technologies for optimizing mobile traffic with respect to signaling activity. Those metrics should correspond directly to the network resources that are overburdened by the excessive background traffic generated by chatty mobile apps.

For today’s blog we will focus on two related measures: the number of connections and time connected. Let’s define what we mean by these terms. First, it’s important to note that when we say “number of connections” we mean device connections rather than application connections. Specifically, a connection occurs when the device radio moves from idle (lowest radio power state) to connected (higher power state), triggered by a network transaction when the radio is idle. Once the device is connected, multiple network transactions can occur as long at the radio remains in a connected state. Similarly, “time connected” means total time during which a device radio remains in the connected state, and is therefore occupying network capacity.

Each time a device connects to the network, it is using up signaling capacity as the network processes the request. Too many devices trying to connect at once can overwhelm the network’s ability to process these requests. Each device connection results in multiple signaling messages, so the number of connections and time connected serve as useful proxies for the volume of signaling activity – which as we said, cannot be observed directly. It should be noted that the ratio between signaling messages and connections varies depending upon the underlying network technology.

The key thing to remember about “number of connections” and “time connected” as metrics is that they correspond directly to the benefit derived by mobile carriers when they deploy Open Channel Traffic Optimization. These measures allow us to effectively track the ability of the software to ease the burden on critical network resources, thus helping mobile carriers to achieve greater network efficiency and lower infrastructure costs.  Specifically, measuring the difference in the number of connections and time connected with and without the software activated allows us to quantify its impact.

If you have read this far, you are probably wondering how effective Open Channel Traffic Optimization is at reducing the number of connections and time connected. To discover the answer, we invite you to download our new white paper, titled “Open Channel Traffic Optimization Carrier Field Trial Results”.

Incidentally, there is also a strong causal relationship between the amount of time that the device spends in a connected state and battery consumption.  We will discuss that relationship in a future blog post.

Posted in Mobile Technology, Network Congestion, Mobile Devices, Mobile Infrastructure, Traffic Optimization | Tagged , , , , | Leave a comment

The Results Are In: Carrier Trials Prove Effectiveness of Open Channel Traffic Optimization

SEVEN Networks conducts trials with mobile operators to demonstrate the effectiveness of our Open Channel Traffic Optimization software. A new white paper presents results from recent trials publicly for the first time.

The trial results confirmed what we knew all along: that Open Channel Traffic Optimization substantially lightens the mobile signaling load on carrier networks and reduces bandwidth consumption. It also significantly extends battery life. To provide someMobile-Traffic-Optimization-Trial-Results hard data around this, on average battery life was 17% longer for devices on which
the software was optimizing mobile data traffic. Two other important optimization metrics showed results that were even more favorable – by a wide margin. To see the full results, please download the white paper (registration required.)

The white paper outlines the trial methodology, defines the metrics used, and provides trial results for six carriers. The trials are designed to help each carrier understand the results that the software can deliver in a full-scale production deployment. Trial users are typically selected from among the carrier’s own employees, and they are instructed to use the phone as if it were their own. SEVEN Networks does not require or request that specifics apps be installed (or not installed), which ensures unbiased results.

Trials consist of a baseline period and an optimization period, each usually lasting about a week. During the baseline period, the software is present on the device, but the optimization functionality is turned off. During the second period, the optimization functionality is activated. By comparing metrics across the two periods, we are able to measure the benefits of the software.

The carriers involved in the trials span three continents – North America, Europe, and Asia – and they have diverse profiles in terms of size, network technology, app mix, and user behavior. The fact that the results were so consistently positive indicates that the product will have a positive impact in a wide variety of carrier environments.

For a full description of these exciting results, we invite you to download the white paper.

Posted in Longer Battery Life, Mobile Infrastructure, Mobile Technology, Network Congestion, Traffic Optimization | Leave a comment

Meet with SEVEN Networks at Mobile World Congress 2014

The Mobile World Congress Conference for 2014 is nearly upon us. Running from February 24-27 in Barcelona, Spain, this year’s event promises to be a perfect venue for attendees to speak to mobile industry product and service providers, and learn more about the latest technology developments, current trends, and strategic growth initiatives.

SEVEN Networks will be there – meeting with mobile carriers and prospective partners, and discussing the latest developments related to SEVEN’s Open Channel product line. These include Signaling Optimization, Policy Enforcement, Seamless Mobility, and Wi-Fi QoE. Open Channel products provide intelligent on-device mobile traffic management and optimization for wireless carriers.

Members of the SEVEN Networks team will be available in our meeting room throughout the four-day event. If you would like to schedule an appointment to meet with us, please email us at sales@seven.com.

We hope to see you there!

Posted in Industry Trends, Mobile Events, Mobile Technology, SEVEN News | Leave a comment

How Chatty Apps Shorten Smartphone Battery Life

Will longer battery life become the next feature battleground for smartphones?

Antony Leather writing on Forbes.com believes it should be because mobile subscribers are growing frustrated with constantly recharging their phones – to the point that they would accept thicker phones just to have longer battery life.

The problems that he identifies are antiquated battery technology and increasingly heavy usage: “The trouble is, few if any manufacturers seem to have cottoned on to just how much each of us uses our smartphone.”

Another very important issue is how much battery power is being consumed when users are not actively using their phones. Even when a phone is to all outward appearances idle, there is a lot going in the background that drains battery life. Smartphones are not connected all the time; rather they repeatedly connect and disconnect during the day as they sit idle on a table top, in a pocket, or in a briefcase.

It’s intuitive and obvious that when the screen is on, it leads to higher power consumption than when it’s off. What’s less obvious is that the activity of the phone’s radio is another driver of battery drain. When the radio is on, the device consumes power at a higher rate that when it’s off. And when the radio state changes frequently – moving from off to on and back again repeatedly – that also leads to higher power consumption and faster battery drain.

Mobile subscribers typically have a few dozen apps installed, and most of those apps frequently check for new data. Frequent updates are intrinsic to the always on nature of the mobile experience. However, a large portion of this constant checking for updates is unnecessary, because no new data is available. Even so, those chatty apps keep checking. This background activity causes the device to be connected for longer than it needs to be, and it also causes more frequent changes in radio state. This in turn leads to accelerated battery drain.

Signaling optimization reduces both the time the device is connected to the mobile network and the number of connections. The immediacy of the mobile experience for the subscriber is not adversely impacted, because it’s the unnecessary background activity that is optimized away. By reducing both the time that the device is connected as well as the number of changes in the radio state, battery life is significantly improved.

Posted in Longer Battery Life, Open Channel Signaling Optimization, Unnecessary Signaling | Leave a comment

Come See SEVEN Networks at LTE North America 2013

The issue of mobile network signaling will be the focus of an entire day at the upcoming LTE North America 2013 conference (November 20-22 at the Westin Galleria in Dallas, Texas), and the SEVEN Networks team will be there.

The Signaling Focus Day at the conference, on November 20, will give attendees the opportunity to participate in interactive learning sessions to gain a deeper understanding of the issues and challenges of mobile network signaling.

SEVEN Networks will be addressing app-related signaling in an afternoon panel discussion titled “Managing the Impact of ‘Chatty’ Apps and Devices Upon 4G Networks,” which features Ross Bott, CEO of SEVEN Networks and Monica Paolini, President of Senza Fili Consulting among the panelists. Additional panelists will be announced shortly.

The panel discussion will explore the issues and ramifications stemming from excessive mobile signaling traffic, which stresses network resources, increases operator costs, and adversely impacts the subscriber experience.

Ross will discuss the advantages of stopping unnecessary signaling at the source – the mobile handset. Compared to other solutions that manage mobile data traffic from inside the core network – a software presence on the handset enhances network efficiency by optimizing signaling before it can impact the network.

A variety of SEVEN team members will be on hand during the entire three-day event to meet with wireless carriers and potential partners. Please be sure to email us at lte-na@seven.com to schedule a meeting time with SEVEN Networks during the conference. Those interested in speaking with SEVEN Networks more informally are invited to stop by our exhibition pod on Signaling Focus Day.

If you have not yet registered for the conference, but would like to attend, we can provide promotion codes for a limited number of free (for carriers) and discounted (for partners/potential partners) conference passes. Availability is limited, so if you are interested in this offer, please contact us as soon as possible.

We hope to see you there!

Posted in Network Congestion | Leave a comment

Taming Mobile Signaling Shown to Reduce Wireless Carrier Costs

Carriers have long known that unnecessary mobile signaling increases their costs, because it forces them to add capacity to maintain service levels. Many carriers are aware of potential countermeasures, such as signaling optimization, but have been uncertain about how much they stand to save. A new white paper available on the SEVEN Networks website titled “The Taming of the App: Measuring the Financial Impact of Mobile Signaling Optimization” answers that question.

Produced by industry analyst Monica Paolini of Senza Fili Consulting, the white paper models the financial benefits of implementing Open Channel Signaling Optimization, which is designed to significantly reduce smartphone signaling and associated bandwidth consumption.

Though transparent to mobile device users, their smartphone apps – which include games, social media, email, weather, news, etc. – constantly poll the network to search for updates. In aggregate, across multiple apps for multiple users, this background activity creates a heavy mobile signaling load, as devices must constantly connect to the carrier network.

Some mobile carriers anticipated that excessive signaling caused by chatty apps would be partially mitigated with the implementation of 4G/LTE networks. However, the proliferation of smartphone adoption, along with the explosion of free or inexpensive mobile apps, will continue to drive increased mobile signaling.

Nielsen reported that in 2012 the average mobile device had 41 apps, compared to 32 in 2011. It’s safe to say that this number will prove to be even higher for 2013 and beyond. Even though a typical user has several dozen mobile apps installed, only a few of them become frequently used favorites. Even apps that are rarely used can still generate substantial background activity.

In its exploration of this issue, the white paper examines the impact of network traffic on both the control plane (signaling/background activity) and the data plane (user-driven activity), and analyzes the cost savings that carriers can realize from using Open Channel Signaling Optimization software to manage and optimize app-driven signaling. The calculations are based upon optimization results achieved by the software in actual carrier networks.

The findings show that app-driven background traffic increases carrier network capacity requirements – and hence operating costs. At the same time, because smartphone subscribers do not directly initiate the app-related background activity, it becomes difficult for operators to monetize this activity.

The white paper concludes that carriers can realize per-device savings of $33 over the two-year life of a 4G smartphone by adopting SEVEN Networks technology to optimize mobile signaling. Significant savings can also be realized for 3G devices. We invite carriers interested in learning more to download the white paper or contact their SEVEN Networks representative.

Posted in Hands-On Carrier Control, Mobile Devices, Mobile Technology, Network Congestion, Open Channel Signaling Optimization, Unnecessary Signaling | Leave a comment

A New Way to Combat the Diameter Signaling Storm

Cisco projects a 75% compound annual growth rate for the number of 4G devices between 2012 and 2017, from 60 million to 992 million.  As 4G networks expand and customer adoption increases, the wireless industry faces a new “signaling storm” – this one related to core network signaling using the Diameter protocol.

We have written about how Open Channel Signaling Optimization dramatically reduces unnecessary radio access network (RAN) (mobile) signaling. It can also help carriers to address the challenges of Diameter signaling. To understand how, let’s examine the nature of Diameter signaling.

Diameter and SIP are the protocols in LTE networks that replace SS7, which is used in 3G networks. SIP is the call control protocol used to establish voice, messaging, and multimedia communication sessions. Diameter is used to exchange subscriber profile information and for authentication, charging, QoS, and mobility between network elements.

In 3G networks, the signaling bottleneck is located at the radio network controller (RNC). The bottleneck in LTE networks moves into the core network, at the mobility management entity (MME). However, many core network signaling events have their origin in radio access network signaling, so excessive and unnecessary RAN signaling will exacerbate the coming Diameter signaling challenge.

Diameter Signaling in Depth

The Diameter protocol exchanges information in transactions, which consist of requests from a Diameter client and responses from a Diameter server. The elements participating in the Diameter transaction include:

  • Clients who generate Diameter messages requesting information
  • Servers that respond to the request for information from the clients
  • Agents that route, process, or redirect Diameter messages between the client and the server

The Diameter protocol was originally envisioned to handle things like charging or simple policy control. However, today Diameter has taken on a much broader set of responsibilities. In today’s networks, the functions of the Diameter protocol can be broadly grouped into the following categories:

  • Registration, authorization, and authentication
  • QoS/bandwidth-based admission control
  • Charging
  • Location

It is beneficial that Diameter has been adopted for all these uses and that it has been able to accommodate them. The downside is that there hasn’t been a focus on the network-level robustness of the protocol. Congestion management, peer congestion control, and redirecting on failure were not considered part of the protocol. Nor were they designed into each network element. This has significant potential to create problems in light of the following:

  1. Increasing traffic volume: According to Acme Packet, by 2015, 44,000 Diameter transactions per second (TPS) will occur for every one million subscribers. For a moderately sized LTE deployment of five million subscribers, a mobile service provider will need to process between 220,000 and one million Diameter transactions per second.
  2. Proliferating network elements: LTE networks are characterized by more boxes and increasing complexity. This means that even more signaling is required for these boxes to communicate with each other.
  3. No network-level means of managing signaling: Carriers often deal with signaling at the level of individual network elements rather that at the network level. That breeds inefficiency and far too many point-to-point connections. As the signaling load grows, the resulting “n-squared” increase in core signaling traffic can quickly overwhelm nodes in the network.

All of the resulting signaling has resulted in network outages because the servers involved in processing various AAA, QoS, or charging functions are not equipped to deal with spikes in volume.

Controlling Diameter Signaling

To meet such challenges, a number of vendors are offering products that they call Diameter routing solutions. These products sit at the center of the LTE core network, and are designed to centrally and intelligently help distribute and scale network signals. These new devices focus solely on managing and routing signals, and they have very powerful processing capability.

Diameter routing solutions are one way of managing the Diameter signaling storm. But it’s important to remember that a significant portion of Diameter signaling originates as RAN signaling when devices connect to the network. That is to say, RAN signaling is upstream from core network signaling.

Not every Diameter signaling event originates in the RAN, but many of them do. A complementary approach for reducing Diameter signaling is therefore to reduce the number of times that devices connect to the radio network, and hence reduce the associated signaling messages.

Chatty apps constantly poll for updates, which causes devices to generate mounds of RAN signaling that in turn drives Diameter signaling in LTE networks. Often this mobile signaling is unnecessary in the sense that no updates are available – meaning that the signaling activity yields no benefit to the end user.

It makes sense to optimize signaling at the client before it ever generates a signaling event, and this can be done without adversely impacting end-user experience.  That’s where our Open Channel Signaling Optimization comes in.

By dramatically reducing unnecessary mobile signaling, Signaling Optimization lightens the load on the MME in LTE networks. (It also lightens the load on the RNC in 3G networks). Carriers concerned about the Diameter signaling storm should consider Signaling Optimization to address this important root cause of signaling overload in the LTE core network.

Posted in Diameter Signaling, Network Congestion, Open Channel Signaling Optimization | Leave a comment

All Mobile Signaling Is Not Created Equal – Unnecessary Signaling Defined

It is well established that mobile signaling is a primary driver of congestion in carrier networks. Carriers lack control over the behavior of chatty mobile apps, and apps are not optimized to make the most efficient use of network resources. Apps constantly poll for new data, which causes devices to signal the network – even when no updates are available. The ever-increasing number of mobile devices and chatty apps combine to create what we at SEVEN Networks characterize as a “signaling storm”.

Carriers are interested in relieving network congestion by reducing their overall signaling load, and yet some signaling is necessary to deliver the always-on immediacy of the mobile experience for subscribers. It’s the unnecessary signaling that presents an opportunity for optimization.

What exactly do we mean by “unnecessary signaling”? Simply stated, unnecessary signaling is signaling associated with traffic that yields no benefit to end users. Specifically, this occurs when a device signals the network so that an app can check for updates, but there are no updates to be had.

Unnecessary signaling is precisely the type of mobile signaling that can be optimized away without adverse impact on the end-user experience. By minimizing unnecessary signaling, it’s possible to make the subscriber base better off without making any subscriber worse off. You can think of it as eliminating the waste from the system. That is the very definition of an optimization opportunity.

Wireless carriers who are interested in addressing the mobile signaling storm and making more efficient use of existing network infrastructure would be well served by considering Open Channel Signaling Optimization. We invite you to learn more by visiting the product page on the SEVEN Networks website.

Posted in Mobile Devices, Mobile Technology, Network Congestion, Open Channel Signaling Optimization, Unnecessary Signaling | Leave a comment

Open Channel Platform Now Offers Plug-and-Play In-Network Option

Software Provides Outstanding Time-to-Value for Mobile Operators

Historically, in-network deployment of software solutions for mobile data networks has been (for the most part correctly) perceived as laborious, complex, and time consuming. There are several drivers of this complexity, including the number of integration points, amount of custom code required, size of the bill of materials, and third party software requirements. The latest release of the SEVEN Networks Open Channel product family now features plug-and-play in-network deployment, minimizing these sources of complexity.

The Open Channel platform now gives mobile operators an additional option alongside hosted deployment, which was offered in the previous version of the software. Both hosted and in-network implementations include the Open Channel client, which extends mobile traffic management and optimization from the network to the handset. Managing data traffic at the client is a superior model compared to traditional approaches, because it occurs before the traffic can impact the radio access network.

The server component is what differs between the two deployment models. The in-network model enables the server component to reside in the carrier’s data center, where the product is managed with hands-on carrier control via a simple administrator interface. Most carriers will choose this model for long-term, large-scale use. In the hosted model, the server component resides in the SEVEN Networks data center, where the SEVEN technical team manages the product based upon carrier-defined parameters. The hosted model is recommended for initial device launches while in-network deployment is being prepared, and offers the shortest deployment time of all.

Our in-network deployment model is different than what carriers have come to expect from most infrastructure software solutions in that it is truly plug-and-play. It streamlines the deployment process by addressing the drivers of complexity. The software can run on two single rack unit servers for an initial deployment, and additional servers can be added to scale to tens of millions of users. It uses industry standard open source operating system and database software, and requires minimal network integration and no custom coding. As you might imagine, all of these design choices streamline the deployment process significantly.

The SEVEN Networks development team really did their homework to make this new in-network option simple to deploy, with outstanding time-to-value for carriers.

Visit the Open Channel product family page to learn more.

Network Diagram

SEVEN Networks Open Channel software products include a client component and a server component. This diagram illustrates the recently announced plug-and-play in-network deployment model for the server component. Regardless of the server deployment model, the Open Channel client extends carrier control to the mobile client.

Image

Posted in Hands-On Carrier Control, In-Network Deployment, Mobile Devices, Mobile Technology, Network Congestion, Open Channel, SEVEN News | Leave a comment