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Comment by maxerickson | Hacker News Reader

People in a stadium aren't going to be quite as focused on their phones, but lots of people in a tight space isn't an unusual occurrence for networks.

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Stadiums have issues with this too. I was at Marlins Park for the All-Star series. During the Home Run Derby I had press access, which had special Wifi credentials on a completely separate network.

It was down for the entire game. A lot of hotspots popped up in the press area.

The during the actual All-Star game I tried the regular stadium Wifi. It was down for most of the game.

T-Mobile was up for most of the game, so I was still able to publish photos and read people's reactions. A good thing as T-Mo was the main sponsor for the games.

It's a challenge, but a very well-characterized one that all enterprise-grade access points are built to handle. Lots of access points, with radio power turned way down to prevent neighbor interference, and channels selected to avoid overlap with neighboring APs.

Shameless plug - my ex-employer Meraki is particularly good at supplying these systems for events, since they have automatic channel-selection and good tooling for selecting power levels, and let you set up configurations at your leisure that the APs will use as soon as they get an internet connection and fetch the configs from Meraki servers.

~15k people in a small section of Grant Park all trying to play a somewhat data-intensive online game that requires constant communication with servers is a VERY different activity stream than people in a stadium. Might be closer to think of those people in a stadium all trying to stream video of the event.

Is the game that data-intensive? What data is there to send/receive that you're comparing it with streaming video?

how many people are live streaming a concert at a given moment? maybe 5-10 on periscope, in addition to maybe 2x that number on facebook. definitely not 15k.

The game uses google's protobuf protocol which makes communication more efficient and the game updates (I can only tell from <= 0.35 analysis) all 10-30 seconds like loading pokemon spawns and map entities of the current map area.

The most expensive data in 0.35 was:

- Pokemon models (They were dynamically loaded but cached then)

- Pokestop images (Server sends image url and client searches for a chached version)

- Syncing the player state with the client (Inventory, rewards, egg states..)

- Updating the map (Future pokemon spawns, pokestops/gyms in view..)

If a player is idle and doesn't move, just keeps farming a single pokestop and battles sometimes, then it should be relatively low cost since the game doesn't use a realtime communication (It's actually HTTPS based lol).

The pokemon models are loaded over the network? Whatever for? Seems like a big waste of precious data

So you can add/update them without doing an .ipa/.apk update ? Seems really convenient, and a one time deal if it's cached.

Last year I developed a server emulator for the game - On the server's first run, it cloned all models from the official servers to a local folder. The download urls and the models itself were encrypted, also their urls got disabled after ~24 hours. Other informations like how big a model gets displayed inside the game world was declared inside a GAME_MASTER file. When connecting to the custom server, the client asks for the GAME_MASTER file and the models as needed. It was pretty fun to edit these and send the players custom models like a GIANT snorlax or a red pikachu. I'm not 100% sure, but I think the GAME_MASTER file even contained a "model signature" to trigger a forced model update, so it's possible to overwrite already cached models. In the first weeks Niantic broke the model of Starmie (it turned full black) and I'm pretty sure they fixed it without a full game update. You can checkout the emulator project here: https://github.com/maierfelix/POGOserver

I haven't actually measured anything, I know when it first came out there was some concern about people possibly hitting bandwidth caps. I think part of the issue may be overhead - it's regularly communicating back to the servers with current location, and getting back a list of coordinates for stops within a certain distance (with a bit of other data), coordinates and other data for Pokemon spawns, etc. It's also using Google Maps data to draw a map of the terrain including roads, water and building outlines, so all of that is also something that changes as you move around. Finally, people are also supposed to "spin" Pokestops and gyms, each of which also has a photo of the piece of artwork, etc. that the stop is located at. Along with the map data, those photos are not preloaded in the app so they have to be downloaded at least once. I don't know how much caching of those images is done - hopefully some, but if they're doing little or no caching then that's yet another chunk of data to pull down.

Looking at the screen and a map, it looks like the game renders an outline for every structure within 600-650 meters of me, so for an area with a lot of structures that could be a fair amount of downloaded data depending on how good their caching is. If their download process isn't good at handling missing data or transmission errors, it could also be pretty vulnerable to problems on a congested network.

Slight correction, as far as I know they were using OSM, not Google Maps.

They use Google for the base map everywhere except South Korea, where they do use OpenStreetMap.

There are rumors that some game features (biomes and such) are influenced by features in OpenStreetMap, but no clear statement from Niantic, just a bunch of weak correlations (like OSM having a path where a bunch of people go and try to play the game...).

There was a big problem where people were manipulating biomes in the game by messing with OSM, so unless there's some sharing going on with Google..?

Base map vs hidden game features. Outside of Korea the base map is 100% Google.

The hidden game features, who knows. Lots of people are very convinced that OpenStreetMap features have an impact. I haven't really seen anything all that convincing, just lots of correlations that could be have other explanations (game analytics, other datasets, etc).

Apparently the game is a few megabytes per hour (this makes sense to me, the map isn't very detailed, a lot of other stuff is very cache-able).

So I think the experience in stadiums will translate okay. Of course it won't be the same, but it's tens of thousands of radios in high proximity.

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