[General Topics] Menneisyys:
Now that there already are some AKU3 devices (mostly MS Smartphones) on the market (for example, the HTC Dash (see for example this excellent Smartphone Thoughts review), and I, as I know quite much about Bluetooth, network sharing (I’m the author of the one and only POST-capable, free HTTP network sharing proxy for the Pocket PC) and connectivity issues of Windows Mobile devices, have been receiving a LOT of related questions (see for example this), I have decided to update my well-known Use your Pocket PC Phone Edition as a modem for your other Pocket PC's” tutorial so that it contains AKU3-related information and to also explain why dial-up connections in the latest, AKU3 version of WM5 behave completely different from earlier operating system versions.

This article will be of extreme interest to anyone using their Microsoft-based phones (let them be either full Pocket PC’s or “just” MS Smartphones) as cellular (GPRS / EDGE / UMTS / HSDPA etc.) modems because it explains everything about this subject, including the changes over the old model.

1. The most important changes, connectivity-wise

There are major changes in the connectivity model of AKU3 when it comes to serving clients that would like to use a Windows Mobile phone as a modem via either Bluetooth or infrared. In the following two subsections, I elaborate on both connection forms.

1.1 Bluetooth: No BT DUN profile any more

In AKU 3+, the Bluetooth DUN (Dial-up Networking) profile is no longer supported at all, only the PAN (Personal Area Network). Now, it’s via BT PAN’s that cellular-only network connections are shared and you have no access to DUN functionality any more.

This means clients discovering AKU3-based Windows Mobile phones will NOT see as modems, unlike with operating system versions prior to AKU3. This means that instead of seeing this (Microsoft BT stack) and this (Widcomm BT stack), you will see this (with the MS BT stack as clients) and this , this and this (three Widcomm-based clients (iPAQ 2210, hx4700 and the Pocket Loox 720)).

The latter screenshots, in essence, show you won’t be able to use Windows Mobile phones with Microsoft BT stack-based clients as the latter have no BT PAN support at all – along with a lot of other types of devices. That is, not so many “client” operating systems (“client” refers to devices that would like to use Windows Mobile phones to access the Net) support the (quite advanced) BT PAN profile as the “traditional” BT DUN dial-up method.

In the following subsections, I elaborate on the PAN compatibility issues both desktop and handheld OS’es. After that, I elaborate on other, related issues like port forwarding and convenience issues.

1.1.1 Desktop OS’es and BT PAN compatibility

On Microsoft Windows desktop PC’s, there is no difference: even the MS BT stack supports joining already-existing BT PAN networks as has been explained, say, here.

On Linux and Mac OS, however, the situation is vastly different: in some cases, only DUN is implemented in some Linux distributions; so is the case with the different Mac OS versions as far as I know as is also pointed out here.

1.1.2. Handheld OS’es and BT PAN compatibility

As far as Pocket PC’s are concerned, the situation here is far worse than that of the desktop Windows case. Here, it’s only the Widcomm/Broadcom BT stack that has always supported BT PAN. The Pocket PC-based Microsoft BT stack doesn’t have any kind of BT PAN client support as can also be seen in this screenshot. This shows PPC MS BT stack clients don’t see any profiles that would make it possible to access the net via AKU3 Phone Edition (or MS Smartphone) devices. Opposed to this is the pre-AKU3 case where DUN was still visible as can be seen in this screenshot (from the already-linked pre-AKU3 article “Use your Pocket PC Phone Edition as a modem for your other Pocket PC's! - a full tutorial”)).

Non-common Bluetooth stacks (like the ones that come with old BT cards – for example, see the original drivers that come with the Belkin F8T020 card – see this for more info) don’t support PAN either (they only support DUN).

Other (non-Windows Mobile) clients that can only use the DUN profile include Palm OS devices (the Palm OS’ BT PAN capabilities are really bad – Lan Access is, theoretically, supported via BT, but not in practice), some (not all! For example, the Sharp Zaurus has BT PAN support) Linux devices (for example, the Nokia 770), some mobile devices with proprietary operating systems (for example, some Garmin GPS units/computers) etc.

1.2. What do you need to know about infrared support?

It, unfortunately, no longer exists in the new Internet Sharing program, as opposed to the old Modem Link.

Right now, on some pre-AKU3 devices like the Wizard (but unlike, say, the Universal, which also has Wireless Modem (WModem)) Modem Link is the only way to use a PPC PE device as a modem over infrared (IrDA). Unlike “traditional”, “dumb” GSM phones, while these devices are also seen as “modems” for other IR devices when Modem Link isn’t active (I’ve elaborated on this, say, here), they can not be used as modems for actual dial-ups without explicitly starting the Windows Mobile phone in infrared modem mode.

The new Internet Sharing only works via USB / BT PAN as can be seen for example in this screenshot of Internet Sharing – the IrCOMM in the drop-down menu is gone, as opposed to that of Modem Link.

By completely abandoning Modem Link, this only way to connect to the outside world via infrared will also be gone. This means you will no longer be able to use AKU3 devices as infrared modems that don’t have additional programs (for example, Wireless Modem) to be used as infrared modems.

Note that some other PPC PE devices (for example, the HTC Universal) have the IrDA-capable WModem, which, currently, is almost the same as Modem Link (except for some fancy receive / send “LEDs”) and, again, still in pre-AKU3 times, seems to be quite redundant (“why double the functionality?”). This redundancy won’t, however, be the case after moving to Internet Sharing (if and when the Universal receives an official AKU3 upgrade) any more, when it’ll be the only phone app with IrDA capabilities.

What’s the point in sticking with IrDA, you may ask? Why not USB or BT instead? The answer is simple: many, for example, Microsoft BT stack-based Pocket PC devices only have IrDA to communicate, even high-end devices like the Dell Axim x51v (if the latter may not use BT DUN any more because of the lack of the BT DUN support in the modem). The same stands for pocket-sized computing platforms like many Palm OS, Linux and Symbian devices – if they contain BT at all, they are unlikely to support PAN.

With the switch to AKU3, none of these non-BT PAN / non-USB-capable clients will be able to access the Net via a PPC PE / MS Smartphone modem any more via infrared either on devices that only have Internet Sharing and not additional connectivity apps like Wmodem.