Will upgrading to wireless N make iTunes streaming faster?

Question

I have Airport Express wireless N.  My laptop and router is wireless G.  When I stream an iTunes song, the first song always start a few seconds into the song.  If I upgrade to all wireless N, will it start faster?  If so, do I only need to upgrade my router or do I also need a wireless N adapter for the laptop?

Answer 1

Of course, it would be impossible to guarentee by upgrading will definately resolve the issue.
It's important to step back to understand the basics that iTunes uses to stream to the AirPort Express Base Station (AX) to see where there may be potential issues.
The AX works only with iTunes v4.6+ and is limited to music files that iTunes can read; ie, 16-bit data only. (An exception is you can use a third-party product like Rogue Amoeba's AirFoil to stream other non-iTunes sources.) These data, though, can be in any file format that iTunes recognizes, from lossy MP3s at the low-quality end of the spectrum to Apple Lossless and lossless AIF or WAV files at the high end. It is also important to note that the AX functions only at a 44.1kHz sample rate. When you play 32kHz or 48kHz data, iTunes sample-rate-converts the data in real time before sending it to the AX.
iTunes uses a QuickTime CODEC to convert audio files to Apple Lossless, and then, uses AirTunes/AirPlay to send them to the AX. In turn, the AX uses built-in software that converts the Apple Lossless to an Encoded Digital Audio format. From there, digital audio is sent to a optical transceiver to convert the electrical signal to an optical one before sending it to the innermost part of the audio port. For analog, the AX has a built-in DAC to convert the Encoded Digital Audio to Analog which is sent to the same audio port.
One operational glitch is the fact that, as the AX doesn't have a local clock circuit, when the incoming data is interrupted, as it is when you change songs in iTunes, there is no longer a digital output to feed the DAC, which loses lock as a result.
... but how does iTunes/AirTunes/AirPlay actually stream to the AX?
It's actually a two-step process: 1) Establish an encrypted connection, and 2) Stream
Upon startup, iTunes initiates a RTSP connection to the Airport on port 5000. The AX replies with a response (Apple-Response) which is the challenge encrypted using the private key stored in the AX. iTunes verifies this value using its public key part of the assymmetric key-pair. Note that this step is performed by iTunes to verify if it is talking to a real AX. The connection is tore down after this exchange. Note: It could be at this point that you are seeing this delay.
Once iTunes establishes a connection to the AX, AirTunes/AirPlay uses the Remote Audio Access Protocol (RAOP) to stream music to the AX. RAOP is based on the Real Time Streaming Protocol (RTSP) but with an extra challenge-response based authentication step. In turn, RAOP uses two channels for streaming music: a control channel which uses RTSP and a data channel for sending the raw data. Periodically, iTunes commuicates with the AX on the control channel to verify that it still has an active connection.