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Device Profile: Grundig Dreamphone G500i

May 15, 2006 — by LinuxDevices Staff — from the LinuxDevices Archive — 19 views

The Grundig G500i Dreamphone is the first Linux-based iMode phone available in Europe, and the first of several planned Linux-based models. Two years in development, it is the result of a hardware design and Linux implementation from Purple Labs, and is available now in France.

Grundig Dreamphone G500i
(Click to enlarge)

Purple Labs is located in the South of France, and is owned primarily by Vitelcom, a phone manufacturer in Spain that has rights to use the Grundig brand for mobile phones in Europe. The Grundig G500i has been available since March through Buoygues (pronounced “Bweeg”), a small French mobile carrier with about eight million subscribers.

The G500i is a quad-band GSM/EDGE phone designed to work with iMode, an Internet-like packet-switched data service that delivers for-pay content using simplified Internet and Web protocols. iMode was created by NTT/DoCoMo; it launched in 2001 in Japan, where a claimed 30 percent of mobile phone owners now use it daily for traffic, weather, news, ringtones, messaging, Internet-compatible email, and multimedia content downloads that include streaming video and simultaneous song streaming/downloading.

iMode services support a variety of network types, including the UMTS 3G networks that are now prevalent in Japan, and GSM/EDGE networks widely available in Europe. EDGE is a 2.75G technology easier touted by Motorola as easier to integrate with existing infrastructure than 3G (354 Kbps minimum) data services. Compared with 1G GSM/GPRS networks, iMode is about five times faster, with actual download speeds of about 225 Kbps in France, Purple Labs says.

NTT has marketed iMode servers to International carriers for several years, promoting it as a way to increase ARPU (average revenue per user). Europe currently has 400 million iMode subscribers, according to Purple Labs, with iMode service available throughout most of Europe.

Purple Labs COO Jean-Marie Andre says that as a relatively “sexy” phone, the G500i could further increase iMode adoption in Europe. “iMode has been slowed by the Japanese handsets, which are clunky. When the Razr [Motorola slim-phone] came out, it took more than a year to get the equivalent in iMode,” he said.

The Dreamphone — a shipping, low-cost Linux handset

The Grundig Dreamphone G500i measures just 3.3 x 1.8 x 0.9 inches, and weighs less than three ounces (85gr). It has an 85mAh lithium-ion battery claimed to deliver 2.5 hours of talk time, or 180 hours on standby.

The G500i's compact size was achieved in part through the use of a highly integrated Texas Instruments OMAP850 processor, which integrates a 200MHz ARM9 applications processor and ARM7 baseband processor on the same die.

Other G500i specifications include:

  • 176×220 display with 220,000 colors
  • 52MB of user file storage, not expandable
  • 1.3 megapixel video-capable camera with flash
  • MP3 player
  • Bluetooth
  • Java
  • Polyphonic ringtones
  • 1,000-name addressbook on SIM card

The G500i Dreamphone's Linux stack

Andre said Purple Labs decided to build a Linux phone platform because “there is a trend to integrate more and more software modules, and you need to use high-level OSes to smooth the integration process.”

However, meeting mobile phone vendor requirements using Linux is not easy, Andre said. “It was a painful choice, made a long time ago. It took two years.”

He added, “Now, we are working with other undisclosed mobile phone manufacturers, because of what we did in the Linux arena. It is understood what an achievement this is.”

The biggest challenges? “To make it invisible to the user that the phone is running Linux. And in cost, the bill of materials has to be comparable to an RTOS phone. Quite a few software components had to be developed from scratch.”

For example, Purple Labs developed its own graphics system, based on the kernel framebuffer. Asked if the kernel framebuffer was fast enough for a multimedia phone, Purple Labs Linux engineer Thomas Lacroix replied, “Our framebuffer has been optimized for the OMAP processor, and it uses DMAs” (direct memory access transfers).

Andre added, “We assessed gtk and qtopia, but they proved not to be compatible with the real-time requirements and footprint we had in mind.”

(Another Linux phone vendor, Mizi Research in Korea, recently told LinuxDevices that it, too, planned to develop its own graphics system, instead of using Qt.)

Andre says Purple Labs started with a MontaVista “LSP” (Linux support package) for the OMAP850, based on a Linux 2.4.20 kernel. “We had to make a lot of updates during the development. We changed the filesystems, did backports from the 2.6 kernel for the USB-gadget library, and video4linux. But we didn't change the kernel.”

Other interesting open source software used in the G500i, according to Lacroix, included the YAFFS filesystem, SquashFS, ALSA sound drivers, libc 2.3.2, busybox 1.0, gcc 3.3.1, and freetype. Commercial software includes the Access browser, a Birdstep database, and a bluetooth stack from Cambridge Silicon Radio. The phone also includes commercial codecs, and the “DoJa” iMode Java implementation.

Lacroix says Purple Labs will release the GPLed components of its design “soon,” but first needs to check with TI to be sure its graphics library does not reveal proprietary hardware design details, since hardware acceleration was implemented. If approved for release, however, the library could help others using the same chipset, Lacroix said.

The G500i uses Das u-Boot, an open source bootloader. However, users will not be able to easily modify the phone to run Linux kernels of their own implementation (a possible GPLv3 requirement). Andre explains, “The core has some security features. The carriers are afraid of what kind of software might be connected to the network if users could run their own “hacked” Linux OSes. For example, think of an application sending millions of SMS messages per second. They expect from us a certain level of security.”

Has the G500i been successful, during its first three months on the market? Andre said, “There was no huge advertisement campaign, because Buoygues is a smaller operator. But the phone is proving to be very robust, according to the figures we have from after-sales incidents. There are very few complaints.”

Despite the challenges of using Linux, would Purple Labs use the OS again? Andre says the possibility is more than theoretical. “Once you have done the first one, the next Linux phones are much easier. We have other products in the works,” he said.

For example, Andre says, Purple Labs would like to develop a single-chip mobile phone design based on a single ARM9 core. “The next leapfrog will be to move to a single-core UMTS chipset. That will push the ball a little further in terms of street requirements. We would like to demonstrate that Linux can be used for cheap devices.”

Andre adds, “We've seen a lot of devices running Trolltech/Qtopia, but that's not really promoting Linux, because you need to add $30 to $40 to the BOM. We do not need to wait for ARM11 for Linux to be popular. Mid- to low-tier products can run Linux.”


The Grundig Dreamphone G500i is available now through Buoygues, priced between 10 and 100 Euros ($13 – $127) depending on calling plan and subscription term.

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