Nothing gets the fear, uncertainty and doubt (FUD) machine cranking like telecom executives talking about the impact of mobile data and video traffic. It's not an unfounded concern—mobile data usage is outpacing capacity on many 3G networks—but something about telecom trade shows kicks the rhetoric about regulatory roadblocks and flattening revenue into high gear.
Verizon CTO Tony Melone, however, exuded confidence at the TIA 2011: Inside the Network conference in Dallas about the ability of Verizon's LTE rollout to handle whatever subscribers throw at the network. Melone spoke about Verizon's LTE strategy during a press conference at the show.
Not too long after beginning the Verizon LTE rollout, the 4G network suffered a 24-hour outage nationwide. What else can you say about the source of the outage?
Melone: We had a software problem on an element from one of our key suppliers. Actually, there were a couple of software bugs, and in essence what happened is there was a triggering event that should've been nothing but a little hiccup in the middle of the night. That [hiccup] would've caused one of our processes to go down, [but] we have redundancy [so] everything should've worked fine. This software bug essentially caused the system ... [to] consume all of the processing [power], and then it would go to the next redundant system [where] the same thing happened.
A lot of customers didn't even notice that we didn't have the network fully back to where it originally was, so we decided to keep [our temporary workaround in place] to make sure that as we loaded the new software, it didn't introduce any new problems. That's why it took about a week to [bring the network] fully back to its original state, but from a customer perspective, I think 99% of our customers probably thought it was back with our workaround solution.
Why were LTE subscribers who were affected by the outage knocked down to the 1xRTT network instead of 3G EV-DO, and why weren't standard 3G customers affected?
Melone: When we decided to go down the LTE path, we wanted to make sure that we weren't at a disadvantage coming from CDMA to LTE, versus some of our competitors who were going from HSPA or EDGE to LTE, [which are] in the same standards family. As a result of that, we worked very hard to get something in the standard called eHRPD, which essentially takes EV-DO but makes some changes to the core of EV-DO to make it work very seamlessly with LTE. That seamlessness is all about bringing it together in the core—our IMS core. That's where this software bug manifested itself.
Our 3G customers are not part of that IMS core. Our 4G customers who [would normally back] down to 3G are a part of that IMS core, so that's why there's a difference. Even though they're both on EV-DO, the core that pretty much controls authentication to let them on and off is different between the two.