Integrating Photon for Multiplayer in Mobile Games

Imagine: your mobile Unity game, you integrated Photon, but when switching from Wi-Fi to 4G the connection breaks and players are kicked out of the room. A familiar problem? We solve it at code level: configure playerTtl, reconnect, and manual synchronization so traffic doesn't go to waste. Many developers make the same mistake: relying on the default PhotonTransformView components, leading to excessive traffic and reconnection issues. We offer a proven approach that reduces traffic by 3–5 times and provides stable connections on mobile devices. In 5 years of working with Photon, we've completed 15+ projects for mobile games — from simple lobbies to complex quests with matchmaking. If you want to avoid typical problems and save on traffic, contact us for Photon integration into your game.

How to Properly Synchronize Objects in Photon?

PhotonView is the main synchronization component. Each networked object gets a ViewID. Synchronizing position and rotation via PhotonTransformView is the default — it works, but sends updates on every FixedUpdate, even if the object hasn't moved.

The correct approach: implement IPunObservable.OnPhotonSerializeView with manual control over data sending:

public void OnPhotonSerializeView(PhotonStream stream, PhotonMessageInfo info) { if (stream.IsWriting) { // Send only if significantly changed if (Vector3.Distance(_lastSentPosition, transform.position) > 0.01f) { stream.SendNext(transform.position); stream.SendNext(transform.rotation); _lastSentPosition = transform.position; } } else { _networkPosition = (Vector3)stream.ReceiveNext(); _networkRotation = (Quaternion)stream.ReceiveNext(); } } 

On the client, the received _networkPosition is not applied directly — we interpolate via Vector3.MoveTowards or Lerp using the packet time from PhotonMessageInfo.SentServerTime. As Photon documentation states, this approach minimizes network traffic without sacrificing smoothness.

Comparison of synchronization methods:

Manual synchronization reduces traffic by 3–5 times. For mobile games, this is critical because Photon is billed by CCU.

How Does RPC Work and When to Use It?

photonView.RPC — for events that must be guaranteed to arrive: damage, death, item pickup. RpcTarget.All sends to everyone in the room including sender. RpcTarget.Others sends to everyone except.

Common mistake: using RPC for positional updates. RPC is reliable (TCP-like behavior), adds acknowledgement overhead. For positions — PhotonNetwork.SendRate + OnPhotonSerializeView; for important events — RPC.

PhotonNetwork.SendRate defaults to 20, SerializationRate to 10. For mobile, a balance between traffic and smoothness: 15/10.

Connection and Rooms

PhotonNetwork.ConnectUsingSettings(); // uses PhotonServerSettings asset void OnConnectedToMaster() { PhotonNetwork.JoinRandomOrCreateRoom( expectedCustomRoomProperties: null, expectedMaxPlayers: 4, matchingType: MatchmakingMode.FillRoom, typedLobby: null, sqlLobbyFilter: null, createIfNotFound: true ); } 

RoomOptions.CustomRoomPropertiesForLobby — array of keys visible in the lobby for filtering. Don't pass everything to lobby properties: only what is filtered (region, game mode, map).

Why Do Players Disconnect on Network Change?

Network change. The Photon SDK supports PhotonNetwork.ReconnectAndRejoin() — but only if the room has playerTtl > 0. Default is playerTtl = 0, the player is considered disconnected instantly. For mobile: set playerTtl = 10000 (10 seconds for reconnect).

iOS Background. When going to background, iOS aggressively kills network connections. Photon will disconnect in 5–10 seconds. For games where this is critical — use UIBackgroundModes: voip (with caution, Apple may reject) or graceful disconnect.

Traffic. Photon Realtime is billed by CCU (concurrent users). 20 CCU are free. When integrating, it's worth adding Photon Dashboard for monitoring — you can see message count, bytes, peaks. We include Photon Dashboard setup and code optimization in our work to reduce traffic by 30–50%.