Friday, November 2, 2012

Review of docomo LG L-04D

The docomo L-04D is one of the newer (2012 summer model) "pocket Wi-Fi" solutions to enter the "me too" market that was first pioneered by eMobile in the Japan. Unlike many other devices, this one is LTE. After having used it constantly for a month, I can say that it's definitely a keeper and will be my regular data device for my Nexus 7 — as well as my laptops and Wi-Fi only iPads when I'm on vacation in Wi-Fi less areas.

The actual device comes in either white or red, with a black LED panel lit in blue covering one third of the device. It comes with a Velcro-closing gray pouch with the docomo LTE "Xi" (Crossy) brand on it, allowing you to throw it in your bag without worrying about scratching it. As the pouch is soft, you will still need to worry about pressure from other items in your bag pressing the buttons, though all the buttons require them to be depressed for more than two seconds for them to do anything.

The back thin lid can be pried off to insert the miniUIM (aka "micro SIM") – that is located underneath the battery – by prying the clipon back from the microUSB port. You will need long nails and a little bit of strength and practice to open it up. The IMEI, serial number, factory default SSID (which will be in the form "L04D_XXXXXXXX" where X is a hexadecimal digit, and factory default WPA security key (another different eight digit hex string) are printed.

The actual device is SIM-locked, and will only take SIMs that MNC and MCC set to "Japan" (440) and "docomo" (10), respectively. I do not know if there is an official (or unofficial way) to unlock the device. Furthermore, when the device is in Japan, you cannot select the carrier APN; it is locked to Docomo's data "moperaU" based network. When you are overseas, however, you can select the network provider.

The battery is changeable, and it uses a smartphone-use 1650mAh "L17" battery, which is used by another LG pocket Wi-Fi (the L-03D device that plugs into your USB port) device. The spec sheet says you should be able to get 4 hours of continuous use on LTE, five hours on 3G, and I've used the device hard with a tablet, and I can confirm that I'm hitting that number doing moderately heavy web activity — downloads but no video streaming. The specs claim 160 hours of idle time, but I didn't test this, and it's unlikely you'd ever hit this due to the default auto-idle power off of wifi and the fact that most devices these days are always doing some sort of minimal network activity in the background.

When the device is operating, either in 3G or LTE mode, the whole device will get very warm. In winter it could double as a hand-warmer, especially with the felt pouch.

The microUSB 2.0 port serves three functions:
  1. charging, either while off or while operating
  2. providing a read-only mass-storage USB drive to provide a tethering/"modem" driver for Windows. A driver is not needed for MacOS.
  3. providing tethering/wired internet capability for Windows OS, which is used to access Japanese-carrier mail (
It will behave as a proper USB device and identify itself to the computer with a "LG Electronic, Inc." major/minor ID of 1004:6329. It does not need the USB to have its data pins active or shorted (in other words, all USB chargers should work), and it only needs the minimum amount of current provided by USB (500mA) and can charge and operate at the same time; you do not need a high-current USB charger for it. A charger is not included with the purchase of the device. The other minor purpose the USB port serves is that it's opening hole serves as the leverage point for prying the rear cover off.

I did not test the Windows driver or its tethering capability or mail capability, but there are instructions for setting up the virtual dialing on both Windows and Mac (sorry, no Linux) to access the carrier mail.

It's at thin as a modern smartphone (12.9mm) and much lighter (89g), and has exactly three buttons:
  • a power button, which powers the unit on or off after holding it for 3 seconds. It will also "wake" the device if you've set the power savings mode (set to on by default) if you press it momentarily, and even when awake it will light the LED screen showing the status of the device for about 15 seconds.
  • a Wi-Fi on/off button, which turns the access point on/off if held for 3 seconds while leaving the cell radio unchanged. The Wi-Fi defaults to turning off to save battery automatically after 10 minutes on inactivity. The timeout can be changed in the settings, including disabled.
  • a WPS button. When pressed for three seconds, the device will enter "push button WPS" mode, which allows a Nexus 7 (or other Jellybean device) or anything else that supports WPS to negotiate, within a 2 minute window, the SSID and the password for the device. This is pretty handy, as although you can change the SSID of the device, you cannot change the hard to remember password, which is a 8 letter hexadecimal sequence. The Jellybean-based Nexus 7's WPS function works like a charm here. The extra security concious may change from push-button 2 minute window based WPS to PIN code based WPS through the settings, or disable it completely.
The LTE speed in Japan is very good; I was routinely getting over 80% of the 75Mbps downstream and 25Mbps upstream speeds. In the 23 wards of Tokyo, I did not notice it going into 3G mode for any serious periods of time. Cell negotiation is pretty fast, so if you're underground in the Metro and signal isn't available in the tunnels, you can get about 25 seconds of usage per station between cell handshake completion and loss of signal. I tested it overseas in the San Francisco area; it wanted to connect to either AT&T or T-Mobile, and connected at 3G speeds. In South Korea, it connected to SK.

The Wi-Fi access point does 11b/g/n (you can force it to 11b only, 11b/g, 11g only, or 11n only), but Japanese style, which means 2.4Ghz only (5Ghz is not permitted for use outdoors for 11n or 11a in Japan). You cannot select channel 14 for 802.11b. Japan mode gives you 13 channels, but there is also a U.S. mode (11 channels) as well as a mode for Korea and Canada. You can force it to use a particular channel but the default auto mode will do its best to pick the least congested frequency range. The default encryption is WPA2/PSK/AES256 but you can set it to weaker protocols for devices such as the Nintendo DSi. The DHCP server gives out addresses by default, and allows a maximum of ten (10) simultaneous connections. It supports IPv4 only. UPnP support can be enabled. WAN ping is disabled by default. Like most consumer routers, the IP address range, the default address, etc., can all be changed in the web configuration.

The status screen is mostly icons, but with some Japanese. The most interesting things on the screen for most people will be:
  • whether you're connected to a cell yet, if it's 3G or LTE, and the signal strength
  • how many clients/devices/laptops are currently connected to the device
  • the battery life left
  • the amount of data you've sent/received. This odometer resets every month. While the recommended data plan is unlimited, you can look at this and tell if something is weird with your consumption. You can also set a hard cap via the web Connection Manager.
When connected overseas, the carrier is displayed in a plain font. When connected domestically to docomo, you get a graphical brand rendition of the carrier docomo.
One Wi-Fi client connected
shutdown screen; a couple seconds
boot screen; lasts a few seconds
finished booting, trying to find cell
Connected to cell with 0 Wi-Fi connections
power off and charging
Connection Manager in English on Chrome
The web "L-04D Connection Manager" defaults to address with a hard-coded username of "Admin" and a preset password of "0000". The device is pretty much plug & play, in that most people, especially with WPS, will never need to use the web configuration to make it work. One exception is if you go overseas with it; you will need to confirm the carrier/APN the first time you use it with Docomo's WorldWing overseas pake-hōdai plan. The web interface allows for English or Japanese.  It is PIN protected and defaults to "0000", which can and should be changed through the settings. You cannot change the Wi-Fi password, however. The manager is written in non-complex CGI-ish HTML with some Javascript but nothing at AJAX level and seems to work just fine on simple devices like Flash-less mobile touch screen devices as well as minor browsers such as Opera. The web connection manager controls receiving over-the-air firmware updates for bug fixes, etc. The default setting is to check for a new update every time the Connection Manager is used.

If you've ever used a consumer Wi-Fi router, most of the (non-advanced) features and functionality you expect will be in this interface, including an extremely primitive firewall, MAC address restrictions, etc. 99% of L-04D customers will never need to touch this stuff to make the device useful.

In conclusion, the L-04D delivers what it claims to do, and pretty much stays out of sight / out-of-mind, which is exactly what it's supposed to do. I can now travel to work, with the access point hidden in my bag, using my Nexus 7 to read the news and surf the net while I travel in and out of midtown for work. The performance is as good as it gets speed wise for Japanese LTE, even during peak periods (rush hour). Overseas the performance was not as nearly as fast (3G), but the speed was more than adequate. While I only tested in the 23 wards of Tokyo, I received a LTE signal over a 3G signal 95% of the time (I can force a 3G signal by going underground in my home). If a pocket Wi-Fi device at LTE speeds is what you're looking for, you could do far worse than the L-04D.


  1. Tethering should be just another feature of your smartphone. It's silly to carry an entirely separate device for that.

  2. That's true, but there are still reasons for getting a separate device. The easiest answer is power management. A modern smartphone already stresses it's battery enough (it's got a lot more going on than just a cellular radio). If you needed heavy/continuous tethering capability for more than a quarter of a day, you're probably not going to get that from a smartphone without changing batteries.

  3. Agreed, though my solution is to plug the phone into the notebook and either use USB tethering or just charge while running the wifi tether. The batteries on notebooks these days can typically handle that.

    Though I never carry a tablet - only a notebook - so this is an option for me. (Mrs. SBS has confiscated my tablet for her use.

  4. Sorry if I missed it, but didn't you forget to mention the monthly price and data limit?

  5. Tethering is a feature of smartphones. However, it's useful to have a dedicated device for battery reasons and for contract reasons (these things are way cheaper than a cell phone contract).

  6. I have a L-03D provided by my work, which is nice but limiting due to the USB format. I am wondering if I can take the UIM out of the L-03D and put it into the L-04D or something similar? Has anyone tried something like this?