REVIEW: 4Pockets releases first real Wi-Fi / Bluetooth walkie-talkie Pocket PC application 4Talk!

UPDATE (08/09/2006): the bugfix, 1.1 version of 4Talk has just been released. It contains the following bugfixes:

  1. Fixed the 100% CPU usage
  2. Fixed the occasional lock up when IP address changes.
  3. Fixed buggy Signal Strength meter in FULL duplex mode.

The review of the original, 1.0 version follows:

My readers may have already read my articles / posts on Microsoft (MS) Portrait and Gphone here and on various Pocket PC discussion boards / newsgroups (see for example this article). They already know how cool it is to have LAN voice phoning capabilities that don’t require any kind of Internet connection (Skype and the other voice phone programs do need it - that is, they can't work without a real Internet connection -; this is why I don’t list/discuss them in here).

The latest and really revolutionary application in this area is 4Talk by 4Pockets. 4Pockets has already produced some really fine sound applications (AudioBox, PocketRTA (Pro), Auto Tuner) and multiplayer games (4Connect; The Great Gold Rush); the first child of the marriage of these, that is, networked voice communication applications, is 4Talk, which has just been released. (Note that, in addition to multiplayer-enabled titles, they have also released some really great single player games you will definitely want to check out. For example, I especially recommend their Super Elemental (one of the best color matching titles with really great in-game music and explosion effects), Particle Wars (a great vertical scroller; while not as good as SkyForce (Reloaded), I still heartily recommend it), Marble Worlds (a very good Marble (Gyroscope) clone) and some other titles. See the Roundup of All Pocket PC Games Part I for more information on them.)

The homepage of the application is here (Handango page here). the current, reviewed version is 1.0.

The desktop Windows client, connected to three PDA’s and another desktop Windows client in my tests.

4Talk is something like the often-spoken-of “walkie-talkie” functionality of certain Nokia mobile phones. It makes it possible to use your wirelessly (preferably in a Wi-Fi peer-to-peer (p2p) network) connected PDA to speak and broadcast messages to each other.

Differences between 4Talk and other LAN-capable applications (MS Portrait, Gphone)

The biggest difference between it the free MS Portrait and Gphone is the completely different approach to networking and broadcasting. 4Talk is a multicast-enabled walkie-talkie, which can broadcast to several receivers at the same time. MS Portrait and Gphone are completely different animals: they are strictly peer-to-peer communicators, which, therefore, only allow for two parties to speak to each other at the same time.

Therefore, it’s pretty hard to compare 4Talk to MS Portrait / Gphone – they are meant for an entirely different usage area and, in this respect, 4Talk is indeed revolutionary - no other app offered the same on the Pocket PC so far.


  1. Multicast discovery (unlike with Portrait, you don’t need to enter IP addresses of other people on the LAN to call)
  2. Ability to talk to (broadcast to) any number of receivers on the LAN, not just one
  3. Many participiants may speak at the same time (that is, the channel is not locked just to one speaker); all the receivers will play all the (concurrent) incoming transmissions. This is just great!
  4. Transmit button redefinable, unlike with Portrait, where only the Action button can be used for this kind of functionality
  5. Much better full duplex mode than MS Portrait! Here, you only need to enable full duplex mode on devices that are actually capable of (acoustically) separating the mike and the speaker (and are also supported: unfortunately, the VoIP speaker in the Pocket Loox 710/718/720 isn't) or used with wired/Bluetooth headsets to do this. On them, you can talk and listen to others' broadcasts at the same time. Others (ones that would have bad acoustic feedback between the mike and the speaker) do not need to enable full duplex mode – only the fortunate ones that have (supported) full duplex capable devices and/or headsets. With Portrait, this is impossible – there, both parties must enable full duplex mode which, unless both of them use full duplex-friendly PDA’s and/or headsets, will inevitable result in annoying acoustic feedback.
  6. Runs flawlessly even on the slowest Pocket PC’s (non-overclocked HTC Wizard too!), unlike with, say, Skype.


  1. No file transfer / text messaging capabilities, unlike with Portrait
  2. You can’t dynamically change the PCM encoder (the sound quality) used on one PDA, while keeping the old on the others: clients, unlike with Portrait, won’t dynamically change to the new format. This is a banal mistake in the app and can, in my opinion, be very easily fixed. (Fortunately, clients display what sound format the sender is using and can, consequently, quickly switch to it – by hand, of course.)
  3. Buggy: 100% CPU utilization even when idling on all my test devices, unlike with Portrait. If you use this app, it will chew through your battery really fast!
  4. Useless over BT PAN with more than 3 simultaneous, receiving users (not that BT PAN could be used for anything meaningful in this setup because of the very bad range) – the clients just (temporarily) lose (and, then, automatically reconnect, but, then, the message will already be gone) each other and only parts of the broadcasted messages will be heard (if at all). An example of how useless BT PAN can be: If you use the best-quality codec (for example, the 11 kHz/16 bit one (which translates to 22 kbytes/second)), two simultaneous transmissions at the same time will result in choppy sound (44 kbytes/s is just too much for Bluetooth, which has 723 kbit/s theoretical and about 300-400 kbps practical maximal throughput speed.)

    This, of course, isn’t a problem with Wi-Fi because of the much better bandwidth reserves.

  5. Unfortunately, it doesn't support the dedicated Voice over IP (VoIP) speaker instead of the standard one on the Fujitsu-Siemens Pocket Loox 710/718/720. This means Pocket Loox 710/718/720 users can't use the VoIP capabilities of their device. This could be fixed, as has also been done with some other VoIP apps.
  6. Only usable through LAN’s, not even between LAN’s unless multicast packets are let flow through them (which is highly unlikely). This certainly reduces its usability – the range of a single Wi-Fi P2P network is limited.
  7. When the transmission of more than one participiants is being received, the name of only one of them is displayed. While this is perfectly OK when only one participant is broadcasting at a given time, with parallel transmissions, it can be a problem. This could be fixed too.
  8. The blurb refers to “Signal Strength Meter”: don’t think it’s a Wi-Fi / Bluetooth signal meter – it just shows the strength of the incoming voice, which has nothing to do with the actual wireless signal strength. That is, this meter is nothing more than just a useless toy.
  9. (The numerous typos in the accompanying PDF manual could be fixed.)
  10. Transmit button anomalies:
  • On the x51v, it works in the “you can speak while you’re keeping the button pressed” mode
  • On the HTC Wizard and the Pocket Loox 720, it works in the “press once to start and when you’re finished, press another button (which you must find first – for example, on the HTC Wizard, it’s the left WM5 softkey) to stop”

What could be improved?

If broadcasting is only used for discovering, giving users the ability to enter the IP of the receiver, the functionality of the app could be greatly enhanced. Of course, it’d require a MAJOR rewrite / enhancement of 4Talk (a completely new networking protocol should be added etc.)

Bugs like the 100% CPU utilization bug must be fixed, preferably along with the hardware button-related problems. Also, the question of different sound encoding formats could be addressed and the bandwidth-friendly GSM codec used to greatly reduce the network load (see the BT PAN problems with more than 3 receivers). Pocket Loox users would surely welcome explicit support for the built-in VoIP speaker too.

HP iPAQ hx4700 WM5 compatibility could be added (now, the app just crashes upon start). Note that it runs great on my other WM2003+ (the app, unlike Portrait, which is compatible with all Pocket PC platform, isn’t compatible with pre-WM2003 operating systems) PPC’s.

These remarks are, of course, just recommendations. Even without 4Pockets' implementing them (except for the 100% CPU utilization bug, which should be addressed), this application remains great and highly recommended.

Example screenshots

HTC Wizard talking to a Pocket Loox 720 and to a Dell Axim x51v on a Wi-Fi peer-to-peer network (also notice that “Signal strength” is only active upon receiving!)

Main menu

Pocket Loox 720 transmitting to three other clients

The selectable sound quality types (as can be seen, no GSM or other bandwidth-conserving vocoders are available, unlike with the really bandwidth-friendly Portrait)


As with most 4Pockets stuff, this title is a gem and is highly recommended. I do hope, however, that at least the 100% CPU utilization bug will be fixed to conserve battery power.

Comparison chart

(Note that I don’t list Gphone in here because 1. its feature set is a subset of that of MS Portrait 2. it’s no longer supported or even hosted by the developer.)

App:4TalkMS Portrait
PlatformsPC, PPCPC, PPC, Smartphone
Interoperability with other clients?-MSN Messenger
Networking modelBroadcast; LAN only!Flexible TCP/IP
IP rangeLAN onlyAnywhere over any kind of TCP/IP connection
Network must be set up…Manually (Wi-Fi P2P, BT PAN)Manually (Wi-Fi P2P, BT PAN, internet)
Finding others?Automatically (LAN broadcast!)Manually (you must enter his/her IP address if you do not use an online directory)
Conference call; broadcastingBroadcast: any device on a given channel will hear the message; multiple parties may speak at the same time- (only two parties may converse)
Text chat?-+
File transfer?-+
Online users’ directory? (To see who’s online)+- (needs a central Internet server (and Internet connection) for that)
Broadcast discovery (lists everybody “online” without any central directory)+-
Morse / Beep button+-
Full duplex?+; works wonderfully; may be used selectively+; it’s clearly inferior to that of 4Talk: both parties must enable it to work
Selectable / usable codecs / vocodersStandard PCM (in four configurations: 8/16 bits and 8/11 kHz sampling)PCM, GSM, pre-PPC2k2 Mobile Voice; GSM/Mobile Voice can’t be used at the same time for send/receive
Hardware button to toggle sending?+; configurable; works differently on different devices; on some, it doesn’t finish sending+, Action button only, can’t be redefined. Two modes: Press and talk; Click to talk.
CPU usage while idling?100% (!!)10-15%; upon network errors or configuration changes (for example, a new client joins the BT PAN network), may jump up to 100%
Compliance?WM2003(SE), WM5; NOT with the WM5-upgraded hx4700!Every Pocket PC platform (even PPC2k)

I’d like to point out again that comparing 4Talk to MS Portrait is pretty much of an “apples to oranges” comparison – these two applications are meant for entirely different purposes. However, a comparison chart like this is a very nice way of understanding in what 4Talk is revolutionary and how it is different from the previously-available voice communicator applications.

UPDATE (08/08/2006): PPCT frontpage

UPDATE (08/12/2006): AximSite frontpage

Du sollst 4Pockets (z.B. marketing [at] 4pockets [dot] com und support [at] 4pockets [dot] com ) ein E-mail zuschicken.

Did you follow my Wi-Fi P2P tutorial?

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