Reader Forum: How telecom signaling can save cell networks

Editor’s Note: Welcome to our weekly Reader Forum section. In an attempt to broaden our interaction with our readers we have created this forum for those with something meaningful to say to the wireless industry. We want to keep this as open as possible, but we maintain some editorial control to keep it free of commercials or attacks. Please send along submissions for this section to our editors at: dmeyer@rcrwireless.com.
LTE is too good for its own good: It has changed the mobile subscriber mindset. No longer do we live with “good enough.” Now, we expect to be connected to the Internet everywhere, and we want that connection to be fast.
But with more and more data-hungry smart devices in use, the LTE networks, at some point, are bound to let us down. The carriers know that point is coming and are planning ahead. How else could you explain the explosion of Wi-Fi offloading – which experienced an astonishing 875% growth in 2013 – in the United States?
The well-documented onslaught of mobile data traffic is driving the viability of Wi-Fi networks as a way to improve mobile network capacity and improve coverage for mobile carriers. In short, U.S. carriers are aggressively pursuing offloading mechanisms to make sure even their LTE networks, which are 10- to 20-times faster than 3G networks, don’t get clogged up. Globally, there are similar concerns. There are more than 207 million global Wi-Fi hot spots, and that high number is partially driven by subscribers who want to pay the least amount possible and will frequent a coffee bar in order to use free Wi-Fi, and because carriers want to avoid overloading networks.
Roaming onto Wi-Fi, a process through which customers maintain service as they travel by accessing a foreign network, is a critical point of service for operators to address. Wi-Fi roaming keeps customers happy, as they’re never without the services they need, and it helps operators expand their areas of coverage without burdening LTE networks. As standards and technology evolve, operators are employing various approaches to provide their customers with a seamless experience as they move between mobile networks and Wi-Fi hot spots.
But from a signaling perspective, what does the expansion of Wi-Fi offloading mean? First of all, it necessitates interworking from one type of signaling to another, usually without the user knowing it. LTE uses Diameter signaling; 3G uses SS7 signaling; and Wi-Fi uses Radius signaling, and there needs to be ways to seamlessly interwork between these varieties in order for offloading to function properly. In other words, the carrier needs to be able to automatically offload users to Wi-Fi once their smartphones recognize a Wi-Fi network, and be able to handle billing accordingly.
Traditional Wi-Fi providers and mobile network operators are both jumping at this opportunity, implementing complementary Wi-Fi networks as a means to expand coverage, decrease costs and improve network functions. Further, Wi-Fi offload allows mobile operators to provide their customers with consistent service and get better returns on network investments by forming roaming agreements with other wireless operators and MNOs and facilitating increased traffic. Wi-Fi roaming hub operators are also involved, as they enable multilateral connectivity between multiple Wi-Fi network operators.
Widespread adoption of this process may not be far off, as implementation is getting easier all the time. The Wireless Broadband Alliance has established roaming guidelines to give its member operators a reference point as they begin to work on roaming solutions, and Wi-Fi operators have several choices when it comes to putting a system in place. First, operators have the option of connecting directly with other operators and forming roaming partnerships that way. If that isn’t a desirable choice, they can also go through a third-party internetwork packet exchange with a wireless roaming intermediary exchange, which allows for roaming across Wi-Fi.
That’s the Wi-Fi side, but cellular networks will also need to adjust for successful roaming. Even though LTE is fast now, device proliferation can only go so far before the networks begin to feel the squeeze. An automatic switchover from LTE to Wi-Fi would enable a better user experience, keeping service consistent and fast, which in turn will keep subscriber churn down. Similar to the WBA’s guidelines, the 3GPP has developed specifications to educate GSM operators about how Wi-Fi networks can integrate with 3G and 4G mobile networks, bringing about those benefits. Plus, the GSMA and WBA are working together to streamline adoption of Wi-Fi roaming and to make the integration of 3GPP mobile and Wi-Fi seamless and transparent to the end user.
When it comes to Wi-Fi offload and roaming, interworking of Radius, Diameter and SS7/MAP interfaces is crucial. By harnessing interworking, operators can accelerate connectivity between different types of networks, better leverage existing investments in infrastructure and upgrade to new technology and architectures in a controlled manner. Without it, networks are in danger of becoming dangerously overcrowded and overworked.