Saturday, November 27, 2010

LOL



Never been a fan of U2 at any time, however one must appreciate Bono's guts for appearing in a video that plays satire on the fundamental hypocrisy of showbiz.

Shtarker: Too bad about all the dead movie stars.
Siegfried: Yes. What will we do without their razor-sharp political advice.

And with late happy turkey day to everybody:D

Saturday, November 20, 2010

Mobile Network 101 Part 2

In an ideal world, there should be a sensible meeting of people where standards are designed and implemented internationally.However the world is not ideal as we know it, and mobile technology was no exception.

Back in the analogue days, US first came up with AMPS, a simple FDMA (refer to part  1 in case you are getting lost here) system on 800MHz FM band; Japan and the UK was soon to follow suit, however because of regulatory limitations they had to use a different variety on the 900MHz band. Continental Europe, however, went into a frenzy of devising their own national standards, none of which turned out to be satisfactory or economically viable after a few years.

Learning from their blunders, European telcos decided to poll their effort together to create a common standard. The collaboration was initially named Groupe Spécial Mobile, however the acronym GSM soon conflated with the term Global System for Mobile. GSM was designed from the drawing pad to be fully digital, modular, and capable of operating on several different frequency bands to suit national regulations. One major point that had to be mentioned separately is the invention of the SIM card, which allows the user to move his number from one phone to another with ease.

People of the present age often take SIM cards for granted, and indeed in New Zealand over 70% of mobile subscribers are using a prepaid SIM. Nonetheless, SIM card is actually a more recent invention. Back in the days when telecommunication was though to be of natural monopoly and AT&T decided what colour is your phone going to be, it is no big surprise that phones are sold hard-wired to a certain network. In Europe, however, many countries have laws in place prohibiting blatant bundling of service with a product. With the technology standardised between countries, there is no longer any excuse to lock users in. SIM cards also allowed people to change their phones more frequently so the manufacturers are actually quite happy with it.

Hence two very different business models developed on two shores of the Atlantic: American carriers grant heavy subsidy for handsets, often offering them free of charge to lure customers into signing a lucrative contract; even GSM phones are often sold locked to a specific network, even after the initial contract has expired. In Europe, most SIM cards are prepaid and carrier locks are virtually unheard of until, you guessed right, until Steve Jobs decided to shove the American way of life down everyone's throat. 

Back then when GSM was rapidly expanding, AMPS evolved very slowly. The IS-54 standard made the internal handling of calls digital to triple cell capacity, while remaining compatible to the older standard externally for a smooth transition. The subsequent IS-136 standard is fully digital, however it came too late and GSM became the effective global standard.

The future of the AMPS family was sealed when a domestic foe appeared. A start-up company in California called Qualcomm pushed digigently for their radically different and innovative CDMA technology. Unlike GSM or AMPS, CDMA does not require a frequency switch during a handover process, resulting in a much "softer" transfer that nearly always goes unnoticed and rarely dropped. While GSM and AMPS are both subject to the limitations of TDM encoding, GSM was being continually developed to minimise any issue but AMPS lacked the momentum, not to mention it was not designed to handle frequent handoffs in the first place. Two major carriers, namely Sprint and Verizon Wireless, embraced CDMA because SIM card (correct term for CDMA is actually is RIM) is not mandatory, allowing the contract-based status quo.

Subsequently AMPS went into a slow but steady decline; service has been stopped in most countries by 2006. To this date only a few networks remain, all of which are in remote regions where the upgrade cost is prohibitive.

The same pattern of change played out in most parts of the world except in Japan, where the AMPS system was simplified to become PDC, which is specialised for the higher user density found in Japan. Because PDC allowed handsets to have lower transmission power, tiny handsets unimaginable elsewhere can be made. Manufacturers became obsessed with making even smaller units, culminating in the PHS system where all cells are microcells covering a radius of less than a kilometer. The domestic market flourished, while the PHS system was exported to gain a huge following in large cities like Taipei and Rio. Notwithstanding their relative success, the Japanese mobile industry became disconnected with the rest of the world for years, overlapping much of the lost decade.

In this chapter above I tried to summarise the development from 1G (analogue voice) to 2G (digital voice), the next chapter will devoted to the entire 3G fiasco of which the effects are still being felt today.

Random Bits of Information

Suffice to say, I am very busy right now with everything in life trying to strangle me. More posts are in the pipeline, and expect frequent updates once I am out of this tar pit.

In the meantime I can make up for the lack of music in recent posts.

Wednesday, November 17, 2010

Sony PRS-350 Impressions

Back to the beginning of 2010, Kindle was the only affordable e-reader of acceptable quality; other offering were either cheap n'nasty or horrendously expensive. Sony's line of e-readers had a mixed reception: the build and system are both excellent, however their screens had a really bad glare issue due to the extra layer of glass where the digitiser is.

A recent trip to SonyStyle cleared up much of my prejudice against Sony e-readers. The latest PRS-350 is especially lovely, with a streamlined aluminium body, beautiful screen and a much improved touch panel that does not glare much if at all.



I tend to speak very positively of Amazon, nonetheless I do feel that they were cutting corners with the Kindle 3 to keep their margins. Omitting a few vestigial bits like accelerometer and GPS can be forgiven, however the plastic chassis had been causing many issues including warped units and broken screens. PRS-350, however, is mainly slimmed down in functionality with no wireless connection and very limited choice of font sizes and no memory card slots.

The relative success of the Kindle is based on Amazon's present customer base, as well as the device's ability to please both ends of the user spectrum, namely from computer illiterate soccer-moms (over the air purchase, delivery and file conversion) to geek major (drag and drop file management, crude system with many possible hacks), while on the usability front it is actually falling behind other companies who are catching up very rapidly. With the glare issue fixed, Sony is in a good position to capture the more mainstream users who is looking for a balanced option.

Verdict

Pros
  • Excellent construction, better than the Kindle 3
  • Small size, light weight
  • Decent touchscreen operation
  • Easy to use, responsive system
  • ePub Support
  • PDF reflow

Cons
  • Lack of wireless connectivity
  • Limited customisations and community support
  • Need a computer to manage books
P.S. Over the weekend, B&H had a deal on Sony e-readers, with PRS-350 priced at US$119.99(approx. NZ$156, around NZ$200 with international shipping). Having just spent some money on booze and canned pineapples, I hesitated on placing an order. However I soon regretted as the price went up to $149.99, much less attractive.

It is available from official channels for $299.95 including GST. You can check it out hands-on at your local Sony outlets. To compare the size of popular e-readers, click here.

Monday, November 15, 2010

Mobile Network 101 Part 1

Last week I went into a recently opened to 2degrees store to see if they have a good mobile data package on offer, only to find out that people who worked there have little actual knowledge of their own merchandise: I asked about WCDMA service outside major urban areas, and they replied that their network is 3G and GSM only.

Seriously?

It is hardly surprising that with a corporate mindset, people are hired on their ability to follow instructions and protocols rather than their own initiative. However when I actually thought about the current state of mobile technologies, it is evident that with so many different technologies and terminologies floating around, it is simply not meant for easy and painless comprehension.

Say, Vodafone NZ is operating concurrent networks, 2G GSM EDGE at 900MHz and 1800MHz, as well as a W-CDMA based, HSDPA capable 3G UMTS on 900MHz and 2100...Well I should probably stop here.

Much of the confusion had been a result of bureaucratic red-tape, political rivalry, human greed and outright stupidity. Hence this new post series is going to strip these terms to be basics in an attempt to explain them. 

Depending on the context, these information could matter a lot or a little to the end user. For example, iPhone owners may find themselves with no 3G coverage while their friends with a $99 Nokia phone gets 3G practically anywhere. Nevertheless if the only activities on their mobile are plain calling and text messages, it is hardly an issue.

Before we head into the confusing world of mobile telecommunication, let us look at the earlier iterations if the copper-based phone system.

Early telephone services are nothing but a simple mesh network of interconnected phones, with your phone physically linked to all your friend's homes. Using a bit simple math, we can soon work out that the number of wires required for n users are n(n-1)/2. The situation soon imploded as every possible wiring space is filled with cables, something has to be done.

 I had to use a less impressive modern example because I cannot find the file photo; for now just imagine the same tangle 10 times bigger.

Then some genius came up with the idea of telephone exchange, which uses human power to physically connect calls by forming circuits. 
The Nutt sisters were the first female telephone operators bought in to replace teenage boys with poor manners; well you cannot expect good manners from a teenager on minimum wage, women are more willing to submit; need proof?

Despite the technologies of phone exchange advanced greatly over the last century, with mechanical then electronic means instead of maiden's hands, the "hub and spoke" model survived largely intact in many other forms of networks beyond voice and data. 


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As an oversimplified rule of thumb, high frequency means shorter distances of transmission and higher bandwidth. A few examples:

Long wave travels by the contours of the earth, hence they require very high masts. Transmission can be picked up from 3000km away on a good day. 
Junglinster long wavestation


Short wave, on the other hand, gets around by getting reflected between the ground and the ionising layer of the atomsphere. Hence they have a range in tens of thousands of kilometers and remains the standard frequency for international broadcasts in this digital age.
Radio Canada's short wave towers

Microwave transmission usually travel by the line of sight, hence they have limited range usually less than 50km. Nevertheless it is of excellent spectrum density and less affected by weather.
Your average rooftop microwave mast, very likely to be a cellphone mast as well; note the drum-like relay antenna and the triangular panel antenna

With higher frequency, range is even more limited and absorption by rain and other obstacles become problematic. However they can be made into good applications such as short range remote controls.
Infrared is invisible to human eyes, however most digital cameras will notice

Hence, there is no accident that mobile phones uses a small section of microwave frequency known as UHF, which offers good range as well as the ability to carry multiple calls from one station.

Earlier iteration of radio phones are nothing more than small radio transceivers connected to the phone exchange system, with many radio masts known as base stations providing service to one area known as a cell and maintaining connection to each phone in small channels of allocated frequency. Calls are handed over to another base station once the user travels into the a different area because the same channel could be used by another device and the late comer has to be allocated a different channel.

All was well when cellular phone are few and powerful such as car phones and large handsets about the size of a hock of ham. Coverage was excellent as one major base station can cover a large radius. For example, Telecom used to have one base station on top of the sky tower for the entire central Auckland, nowadays the same area is served by hundreds to thousands of masts yet call quality is hardly better than what it used to be.

The main reason behind the evolution is that as the number of users increased, existing stations ran out of capacity for calls and had to be divided into smaller cells, and apply some tedious math to make sure there is enough channels to go around.

Conversely, the smaller cells require less power which leads to the further miniaturisation of cell phones; the first generation of true handsets were born.

From left: Motorola Droid(made in 2009), Dr Martin Cooper(born in 1928), DynaTAC prototype (first used in 1973)

Not only do cells need to be smaller in general, extra stations had to be deployed strategically at places where large number of people convene, i.e. train stations, shopping malls and office buildings. An extreme situation would be major sporting events and concerts where tens of thousands of people with cellphones are packed into a small space, often necessitating the network operators to set up temporary cell towers to be able to handle the sheer number of handsets. This adds great complexity to a mature network, since calls are handed over much more frequently over cells of varying transmission power.


Clearly, more measures are needed to be able to fit more users into the finite space of radio frequencies. Digital transmission algorithms are used to compress voice signal into smaller channels, and calls are co-modulated to utilise transmission efficiency as much as possible according to the rule of physics; however the number of calls that can be stuffed into one wavelength is still limited.This is known as Frequency-Division Multiplexing or FDM

A cunning way to get around the issue is called Time-Division Mutiplexing, where each phone is allowed a time slot in the same frequency, maximising use of the same channel. The competing standard is know as Code-Division Multiplexing. Without going too far into the technicalities, imagine FDM attempt at dividing a large hall into tiny cubicles so the occupants will not speak over the voice of each other, TDM as the same hall full of people taking turns to speak; while with CDM everybody talks at the same time, albeit in a different dialect so to avoid confusion. Most current technologies uses one of the methods or a combination of two or more.

For the mathematically minded

Saturday, November 13, 2010

October Political Commentary (3): The Origins of Anand Satyanand

Mutyala Satyanand was born in Fuji to second generation immigrant family who descended from indentured laborers from India.  At the age of 14 he left Fiji to attend high school in Wanganui. A few years later Mutyala was admitted to Otago Medical School, then graduated with an MbChB. Intending to leave for Fiji after his education but his best plans were disrupted by World War II. He stayed on before ultimately deciding to stay and open his own practice in Auckland, where he pioneered what is later known as sports medicine, treating rugby players, cricketers and jockeys of their ailments.

He married a Fijian-Indian Nurse from Suva and started a family. Their son Anand grew up in the eastern suburbs of Auckland, went to Sacred Heart College and, having failed to gain admittance to Otago Med School, took up law back in Auckland and became a lawyer. Slowly he rose to the top as a fair and just man of law by the people. Having worked with both Labour and National, he is the ideal material for his current office.

However, what kind of people is Sir Anand? He belongs to the small class of what I would call the Minority Ascendancy, who are self-made men and women who had worked through the ladders of social hierarchy with their own might. like the AhChee family.(Old enough to remember Georgie Pie? The AhChees started it.)
The Ascendancy always had a ambiguous attitude to their culture identity, i.e. they are partly proud of and partly embarrassed by their origins, and even more aware that they are, ultimately, different to the majority. The social rift back in Fiji runs neatly along lines of ethnicity and religion, while the late Dr Saty would consider himself more Indian, Sir Anand would have tried hard to define himself for the 66 odd years he lived. These are the people of no culture barriers, however these are also the people of nowhere.

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What I thought would be a series of objective informational post ended up being another piece of self-centered reflections and perhaps rant; I promise that the next post will be objecive to the extreme and totally free of personal opinion:)

And it should have been "November" in the title anyway. I ran out of time and energy to write due to exams. In the past two weeks I seriously considered to remove the first two posts because I may never finish the third. Nevertheless, I decided to hold on and finally finished this mini-series. Hence I am a better person, take that.

P.S.Improvements to these posts will be made piece by piece so come back once in a while to see the updated versions.