Category Archives: Radio

Root & Unlock the Samsung Galaxy Gio

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Today I rooted my Optus PrePaid Samsung Galaxy Gio and also removed the Optus carrier locking. Quite a simple process – it was easier than I imagined.

First off you’ll require a few things:

So we’ll start with rooting. You’ll need “root gb updated.zip”. If this link is broken, I have the file, so just post a comment and I’ll update the link.

  • Copy “root gb updated.zip” to your SD card
  • Turn off your phone
  • Press and hold the home button and the power button
  • When recovery mode loads, select” “Add update from SD card” then select “root gb updated.zip” as the update
  • Reboot your phone and you now have the SuperUser app installed

Now we’ll remove carrier locking.

  • Install the Java Developer Kit
  • Install the Android SDK
  • Run the Android SDK Manager and install the “Android SDK Platform-tools”
  • Open the command prompt with administrator privileges
  • Run the command:
    cd “\Program Files (x86)\Android\android-sdk\platform-tools”
  • Connect your Samsung Galaxy Gio to the PC with the USB cable
  • Run the ADB shell. This is a command prompt viewable on your PC which is executed on your phone. The command is:
    adb shell
  • Once the ADB shell has loaded you’ll need to step up into rooted mode. Run the command “su”. After executing this, on the Samsung Galaxy Gio the SuperUser app will pop up requesting permission to grant superuser privileges
  • Now we can start with the actual unlocking. Run the following commands:
    mount –o remount rw /
    mkdir /efs
    mount –o nosuid,ro,nodev –t vfat /dev/block/stl5 /efs
    cat /efs/mits/perso.txt
  • There will now be an 8 digit number that is not entirely made up of 0’s on your screen. This is your unique unlock code. Write it down.
  • Turn off your phone and replace the SIM with a card that is locked out of your phone – ie. a SIM card from a different provider
  • Enter in the unlock code you wrote down when requested
  • Your phone is now rooted and unlocked

I’ll later blog about custom firmware because the Optus firmware is bloatware.

VoIP in an radio broadcast environment

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My article about using Linux inside an FM radio station certainly got some attention. To this day its ranked as my number one blog. I plan on revisiting that article soon as I’ve gained more knowledge and experience in this area.

Today I’m writing about using VoIP in a radio broadcasting environment and why its really awesome for a radio broadcaster over conventional PSTN lines.

A radio broadcaster will typically have 3 unusual telephone devices that most people wouldn’t need.

They’d have a “telephone interface” to connect a telephone conversation to their broadcast which has volume balance capabilities and retains a studio quality audio feed for the studio microphone (instead of phone quality). This can be replaced with a PC running a VoIP softphone and a couple hardware based audio mixers to interface the PC to the studio’s main mixing deck.

They’d also have a recording device that would also retain studio quality audio for the studio microphone so that pre-recorded interviews can be produced. This can be replaced with Asterisk’s Monitor() function without care of studio quality audio. Or, it can be replaced with a PC running a VoIP softphone capable of recording. If the VoIP softphone can’t record in high qualities, you’d just run Audacity simultaneously and later use Audacity to mix the two ends of the conversation together.

They’d also have an external broadcasting unit that uses a specialized modem to encode studio quality audio on a regular phone call so the broadcaster can broadcast outside of their studio. This can be replaced with Audio over IP technologies which are also used in STL (sometimes called STL-IP).

Typically each of these devices are worth several thousands of dollars or more and every replacement can be done entirely with free software.

On top of this, some broadcasters will also have a PBX system provided by their teleco so they can play their broadcast as music on hold and in place of ringing noises when someone calls one of their phone numbers. Asterisk of course can match this functionality.

VoIP is really beneficial for a radio broadcaster for a whole range of reasons, the main one is that expensive hardware can be replaced with free software. The low cost of computer hardware makes it possible to build redundancies into a telephone system that essentially did not have these features to start with.

So now all I’m left waiting on is board approval to begin some migrations to VoIP at my first signup. At a later time I will have to revisit this blog with some more technical detail.

Improving WiFi performance with channel selection

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2.4GHzWLAN-NonOverlappingChannelsOver the weekend I had a look at my wireless routers at home because I found that within my home there were a few black spots in my own home where VoIP worked poorly.

I live practically in the middle of nowhere, there are no more than 10 WiFi routers on my street, and most of these are beyond my targeted range.

I have two wireless access points. I haven’t used WDS because one of the routers does not support it, although roaming between each AP means the DHCP server assigns the same addressing so connections are retained.

I got the Android app WiFi Analyzer while I was out walking the dogs. This app is quite handy as it illustrates the channel overlapping of WiFi routers that are in range. I immediately noticed a street away there is quite a high powered router on channel 6. Interesting because my router nearest to this router was also using channel 6 which explained the poor performance.

So I manually changed that router to channel 11 and instantly noticed the area covered by that router doubled. Quite an improvement for just channel selection.

My second router I was able to install a larger antenna which brings its EIRP up to around 3.5 watts. Its nearest to a neighbour who runs a router on channel 1. This router was using channel 2. So I manually changed the it to use channel 6. I walked down my backyard after changing this and found my whole yard (which is quite large) is covered, when before I only had half the area in coverage.

My work which is in a central business district was more challenging however. There are routers on essentially every channel (when you consider the overlap) within a 100m radius. I did however notice that nobody is actually using channel 3 but instead are on nearby channels. Because of the intense use in the area this seemed like the best pick. Changing the channel here however only made a marginal improvement.

So I suggest that anyone wanting to improve the performance of their WiFi router should look at interference from neighbouring WiFi routers and select the channel they use carefully. Also keep in mind that many WiFi routers are configured to “automatically select” the channel which does not appear to be the best configuration. Typically these routers will end up using Ch 1, 6 or 11 (and in that order of preference).

Wigle.net is another website that is for WiFi Wardriving. They have an Android app where you can contribute data, which if you donate your data to Open Street Map, can use WiFi routers to help determine locations (when GPS isn’t available?). Their maps can be used to discover neighbouring WiFi networks.

Digital Radio for Radio Broadcasters

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I’ve been looking in to Digital Radio the past few days on behalf of one of my customers who is a community FM radio station.

I was interested to find that community radio stations won’t need to buy any new transmitters to enable digital radio – as digital radio is “multiplexed” so numerous stations are squeezed into a single signal with 1000kbits of bandwidth. There are approx 30 digital stations in Sydney which all come from just two transmitters. Because of multiplexing, the law was made that any commercial digital radio transmitters must allocate two ninths of their capacity to community radio stations.

So all we need to do is get backhaul into the transmitter site (whenever it becomes available).

Its also interesting to note that DAB+ uses AAC+ encoding. There is a new uprise in IP based STL (Studio to Transmitter Links). Many STL-IP solutions can encode in AAC+. So with an AAC+ STL-IP, there is no encoding required at the transmitter site.

My customer will be attempting to seek funding for STL-IP even for their FM transmitter but this will cost at least $10,000. Their studio is probably 200 metres from their transmitter, and is currently serviced by FM modulated analogue audio over microwave. There is only one pathway to the transmitter site and if this goes down the FM transmitter goes off air (or transmits nothing).

So the thought is by implementing STL-IP we could continue to use microwave as our primary STL, and we’d need to migrate the microwave link to something IP based. But if the microwave goes down we could utilize the studio’s ADSL2+ link and the transmitter sites fibre optic link to provide a secondary IP pathway. Migrating to STL-IP only makes sense as we could later use multicasting to send the same feed to any digital radio transmitter that pops up in the area.

But something curious about this is that CBAA’s policies on digital radio state that commercial transmitter sites only have to provide one pathway and don’t have to offer any secondary pathways. Meaning a migration to STL-IP would make our FM transmitter more redundant, but digital radio would be more susceptible to failure.

Optus E153 PrePaid Modem

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I’m an agent for Exetel and have to provide Wireless Broadband modems and SIM cards in order to sign a customer up to these services.

Exetel simply resell the Optus network. Their modems cost around $100 and an agent makes about $10 in markups. So flipping through the Australia Post catalogue I wondered why I’m selling modems for $100 when Optus are selling a prepaid carrier locked edition for $49.

Yesterday I activated a new wireless broadband service for a customer so I went to the post office and bought one of their Optus PrePaid E153 modems.

I installed the Exetel SIM card and straight away it worked.

99% of the time I end up installing the software for the customer and give them a quick tutorial on how to use and troubleshoot the service. So I charged the customer $100 for the modem anyway.

But I did however use dc-unlocker.com to unlock the modem so any carriers SIM card will work in the dongle.

So the moral of this: don’t buy carrier unlocked Huawei modems. Check that you can get a much cheaper locked edition thats listed on dc-unlocker’s compatibility list, and unlock it.

New Android Market

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It would appear that in the past few days Google have released a new Android market app.

The new app has a cleaner interface and integration with Google+ so that you can now +1 an app.

I had some troubles though when I first used the new market. Immediately needed to update 4 apps which then locked up my handset. After rebooting though things worked correctly.

SMS Plugin for GLPI

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Today I began works on upgrading from GLPI 0.71 to 0.80.2. Apparently in version 0.72 & 0.72.1 there were some dramatic changes to the plugin spec requiring some code changes.

Some years ago I made a plugin so that when new information is added to a ticket, it waits for 10-15 minutes for further submissions to go idle, then combines them all into no more than 308 characters (2 SMS messages), and sends it as an SMS to the ticket requester (ie. the customer).

So I began migrating the plugin code to support GLPI 0.80.2 which is quite challenging as all the GLPI documentation is in French. Thank God for Google Translate (also that remark calls for a funny joke I heard the other day – “God made me an atheist. Who are you to question his wisdom?”)

I’m also going to begin implementing a second feature of this plugin utilizing MMS and Nokia Smart Messaging so that when a new customer is added, a business card (vCard) is sent to their mobile phone with all my contact information.

Thought I’d blog about it here because I’m not interested in releasing this plugin as open source, however I am interested in licensing the plugin. Anyone want to buy it? Just leave me a comment on this blog if you’re interested.

I should probably also develop another plugin for GLPI for processing credit card payments on tickets instead of processing them the round-about way I do at present. I could even use the PayPal gateway.

Dribble

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Just a few dribbling’s today, thought I’d provide updated information for some old posts.

I’ve blogged about Optus pushing their femtocell to resellers. Exetel are apparently trialing the femtocell with some of their agents. They expect to sell them in 3 months time.

I blogged about sending business cards (vCards) in SMS messages using Nokia’s Smart Messaging v3 (SCKL format). I later discovered that essentially only Nokia devices support this and that most mobiles in use today don’t. Sending vCards as an MMS is the more accepted technique which I presently cannot do as I do not have a gateway. I asked Exetel if they intend on adding MMS in addition to their existing SMS gateway and was told that they intend on doing it within 3-6 months time.

I blogged about migrating my internet hostings from dedicated servers to cheaper Virtual Private Servers and in more numerous numbers. Great idea, still want to go ahead with this, except Jumba at present aren’t offering new VPS accounts and keep pushing back the date they expect to resume offering them. Sucks because I was hoping to make this month my last month with iWeb for a couple of my dedicated servers but so far I can’t do any work on migrating. One of my servers (the one that hosts this blog) seems to continually crash so it would be nice to migrate to something more stable.

I blogged about Google Adsense suspending my publisher account and stated I’m migrating to Clicksor. In the end I found Clicksor quite shocking as there was no way to disable text link advertising (where Clicksor will find words on my page they want to link advertising from). So I ended up going to adBrite who are fantastic. Later that day I also changed the template of my blog and fixed up a few aesthetic issues. Over the weekend for my business website I created something similar to tinyurl.com and bit.ly, where URLs can be shortened – with the intent of later adding adBrite ads so that when I post articles to my businesses Facebook page I have the opportunity to display ads for a few seconds before redirecting users to a website. I also feel more motivated to blog because I’ll now earn a revenue from it.

I blogged about my Samsung Galaxy Gio S5660 that my partner got me for my birthday. I ended up having to send this back for warranty repair at Fonebiz. Randomly it would just lock up – appeared to still be powered on but no buttons would respond until the battery was removed and replaced. Also it would randomly say “File type not supported” when playing MP3 files. Fonebiz’s repair report says they reloaded the firmware (something I can’t do since its Optus branded firmware). But this doesn’t seem to have fixed the issue.

Exetel betters TPG Mobile

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Exetel apparently originally offered this in July but I only just took note. Exetel are now offering a bunch of mobile plans to existing ADSL customers that are better value than the TPG Mobile offerings.

I previously was on the $18.99 plan with TPG Mobile which gave me $330 call spend and 1GB of data. The call rate is charged at 40c per 30 seconds with 35c flag fall. This plan is made available to TPG ADSL customers for $14.99 per month.

Exetel for $15 will give me $440 call spend and 1.5GB of data at a call rate of 49.5c per 30 seconds with a 38.5c flag fall. So the call rate is higher but the included spend is also higher.

If you divide the call spend by the call rate on both providers it shows you the difference.

Exetel you’d get 444 minutes. TPG you’d get 412 minutes.

In addition to this Exetel’s ADSL offerings are already more competitive than TPG.

Good work guys, I just ported my mobile across.

This Exetel plan and others can be ordered from here. Or if you don’t have ADSL with Exetel already, here’s a signup link for ADSL.