This Mobile Life, Baseball Edition
I’m a big baseball fan, more precisely a big Oakland A’s fan, so being out of town on for the last game of the regular season was a big challenge for me. My team (and I say that in the emotional identification sense, not the ownership sense) was playing for the championship of their division while I was unfortunately in Boulder for a meeting of the Broadband Internet Technical Advisory Group (BITAG) so I had to follow the action that fortunately commenced after the meeting was adjourned. So I scooted to the Denver airport and busted out my mobile technology for a real-time stress test.
Before my flight left, I had very good success running the MLB.tv app on an Android phone attached to AT&T’s LTE network. Denver has free Wi-Fi in the airport, but it’s pokey slow and not at all up to rigors of streaming video. MLB.tv broadcasts baseball games out-of-market, which made it the only source for programming in Denver.
The sound and picture quality over LTE was excellent: I got a high resolution picture on the phone that was actually much more satisfying than the previous night’s viewing on my iPad connected to MLB.tv over a hotel’s Wi-Fi network, but I have to rate most of that to the higher pixel density of my smartphone, a Samsung Galaxy S2, over the iPad Original that I have. The A’s came back from a 5 – 1 deficit to take a 7 – 5 lead while I watched with adulation over LTE.
The fun started after I boarded my flight, a Southwest Airlines puddle-jumper to San Francisco that I had chosen for in-flight Wi-Fi and TV, something that alternative carrier United Airlines hasn’t quite managed to figure out so far. Previous experience with the Southwest Wi-Fi/Internet service showed me that it’s a marginal service at best, so I paid for the TV package that allegedly includes MLB.tv as well. After providing them with a credit card and letting them dock me $6 for the two hour flight, I was disappointed to find out that the game I wanted wasn’t available from MLB.tv in the air, despite the fact that MLB.tv was showing it on the ground. This turned out to be a glitch.
While waiting for Southwest to correct their MLB.tv feed, I used their Wi-Fi Internet service to connect on its own sub-optimal path and got about one inning of a pathetic low-res feed with frequent drop-outs before trying the TV path again. This time the game was on, so I got to see the A’s extend their lead. At that point, Southwest responded to passenger complaints about their Internet service by re-booting the whole system, which turned out to be disastrous.
They deliver TV programming to those who buy the TV package over Wi-Fi on the plane, but their outside-the-plane feed is apparently by satellite. The trouble is that the system forgot that I’d paid for the service after they rebooted, so I was locked out. Flight crew told me to pay again and call for a refund after I landed, so I did. Fortunately, the game was still in the eighth inning when I reconnected and got to see the A’s mighty bullpen silence the Rangers’ bats and win the game and the championship of the division.
The experience actually says a lot about where the service bottlenecks are in today’s wireless systems. On the ground, the last hop is the problem. Wi-Fi signals propagate so far that they don’t work well in public spaces such as airports unless they’re carefully engineered to limit overlap between access points and to coordinate well among them. There are systems that do this well, such as the ones that Meru Networks build, but they’re impaired by the presence of too many competing access points. Airports used to be able to limit access points in their airspace, but now that every 4G can serve as a Wi-Fi hot spot, that capability is gone. TV is also a problem for the backhaul behind each cellular antenna and access point, but MLB.tv solves that problem by using multicast to send one packet per program regardless of how many people in the cell (greater than one) are watching. So it’s a scalable system that works as well with high demand as with low demand, and it doesn’t need the buffering that Internet (unicast) video does. With multicast, you don’t congest the backhaul any more with 100 people watching a live program than you do with one person watching. This isn’t something the Internet knows how to do, however.
On-board the plane, the situation is different in that the local system – the Wi-Fi part – is adequate, but the ground link is severely limited. Unfortunately, the particular vendor that Southwest uses has provided them with a system that needs some administration at a level that your typical flight attendant can’t provide. There can’t be more than 20 people using Wi-Fi and TV on their flights, so the local connection between each passenger and the access point isn’t going to get overloaded. The ground link – which apparently uses a combination of satellites and towers on the ground to communicate with the plane – is severely limited, however. It comes and goes, and operates at various levels of capacity as it does. The TV connection seems be separate from this, as it’s much more consistent in quality over time. Like MLB.tv over cellular, it appears to be a multicast service that doesn’t need much buffering and offers a high-res picture most of the time.
The takeaway from this experiment is that we’re not yet at the point where “IP Everywhere” is a practical solution to TV over wireless networks. It’s fine for wireline broadband where bandwidth is predictable and abundant, but over Wi-Fi in public spaces and over cellular and satellite networks in any spaces, we need the scalability that comes from the one-to-many multicast model. Wi-Fi doesn’t do multicast well, and neither does IP, although they both have nominal multicast modes.
This is a problem that has to be solved if we’re going to be “IP Everywhere, Even at Airports and In the Air.”
But the good news is that the A’s won and will open the playoffs on the road against the Detroit Tigers on Saturday. The A’s had the better record, but MLB has decided to redefine “home field advantage” in a way that only commissioner Bud Selig can understand.
By the way, if you’re a baseball fan, you’re also an Oakland A’s fan for this year. See this Tom Verducci column about the love of baseball to understand why.