Have you ever needed to copy some files between Nokia Internet Tablet and S60 smartphone but there was no wifi network signal nearby and you didn't want to search for a running PC? I have, so I decided to take a look at possible solutions that don't involve internet connection (we can't use ftp, e-mail, SMB, etc.) and can be applied to N810 and N95-8Gb. The simplest way would be to use a microSD memory card, but not in this case, so let's focus on local connectivity.

The test setup: N95-2 (a.k.a. N95-8GB) v15.0.015, N810 OS2008 v5.2008.43-7, test file size: 10.045.112 bytes

1. Bluetooth for the beginning
N810's file manager has a great feature - you can simply manage files and folders available in paired devices using Bluetooth technology and supporting file transfer as you normally do with local files (don't ask me, why it's not a 'standard feature' also on S60). This simplifies the task (I don't have to search for 'send via bluetooth' option). Transferring ~10MB test file took 1m42s (N810 -> N95-8Gb and almost the same in the other direction). As you may guess... the more you test, the more different results you get, so I present only the best times. Simplicity is a big advantage here, but I'd expect more from Bluetooth 2.0 + EDR.

2. Wifi in Ad-hoc mode
N810's file manager can also display the shared content of available UPnP media servers (such server is available out ouf the box on S60 smartphones; you may also install UPnP media server on Maemo device, e.g. BRisa). Setting up the wifi ad-hoc for the first time is a little bit tricky (you need to remember to set the same SSID, channel number and you may use only WEP in this mode), but it's easy (and it's done only once). Please note that such network will operate in 802.11b mode, and get up to 11Mb of total bandwidth (according to specs, this is a normal behaviour in ad-hoc networks). Of course, you may use other software to copy data over wifi. The drawbacks of described solution are as follows: you need to spend time to set everything up (but you do this only once); when you want to copy not multimedia file with UPnP server, you have to rename the file extension first (to simulate multimedia file). Transferring the test file took 22s (N95-8Gb with UPnP server -> N810 UPnP client). Turn Bluetooth off, to get best times!

3. USB host mode
This is a very funny and easy way. First of all, you have to have a F-F USB adaptor and install "USB Control" application on your tablet (like Kate's usb-otg-plugin). How does it work? The USB uses a host/peripheral architecture. N810 acts as the host - like PC (USB Master role), and S60 smartphone acts as the peripheral - FAT-formatted flash memory card (USB Slave role). Such "memory card" works smoothly in N810's file manager. Transferring the test file took 20s for the first time, but 4s (!?) for the second time (from N95-8Gb to N810's internal memory; 26s and 16s respectively when transferred in the other direction). If you're curious, you may try 'time cp fileX fileY' or 'time gnomevfs-copy fileX fileY' commands and get... far better 'visual' results (well, it's linux!), but I'll stop at 20s achieved by N810's file manager - the software used for all tests.

I ended up with the following results: 98.48kB/s for bluetooth, 456.5kB/s for wifi and 502.3kB/s for USB. The results may vary depending on test method, testing environment and firmware versions. Bluetooth is currently the slowest, but it will change in the future because of new bluetooth standards - Bluetooth 3.0 HS. Fingers crossed, we'll get it on Nokia platforms soon (theoretically, it's a matter of some business decisions and proper firmware update; practically, we'll have to wait for new hardware-based implementation of chips, like this one)...

Of course, there's still room for improvements e.g. in pairing stage - just imagine holding two devices in one hand and shaking them twice in the same direction (all this goods thanks to accelerometer) or just touching them each other (NFC) to be paired. I would expect to see wireless USB or technologies like TransferJet to complete local connectivitiy options in future devices. Some of mentioned technologies are implemented on a limited number of phone models, but... what is your choice for a new local connectivity highspeed standard?