The Evolution of 1G to 5G - Part 1

Wireless Communication has a pretty strong history, moving from 1G to 5G now. There surely are a lot of things that are left to be understood, and a lot of other terminologies that we still are not clear about. For example, the difference between WCDMA and CDMA, or the fact that LTE is actually not 4G since it does not fulfill the entire criteria set forth by 3GPP, and IMT Standards. So, before we bullet out the historical advancements, we try to understand what it all means in the simplest language possible. For this post- it extends only up to some part in 3G, the rest to be covered sometime later. Also, in the some of the later blogs, we will see on how the data rates actually evolved, and what is Long Term Evoltuion with added features like LTE-Advanced, and how is that now marching towards 5G. In this blog, with each technology, we also bullet out the historically significant things that helped in the evolution. We try understanding things by a new conference room analogy so that we can relate to on how things were though of.

 

The Beginning- FDMA=> TDMA=> CDMA (Conference Room Analogy):

Different people in different room- FDMA

One of the first proposed architecture/protocol for communication happened to be FDMA, which means Frequency Division Multiple Access. Let me explain this through the analogy of a conference call room, on how slowly the technologies evolved. FDMA has been related mainly to 1G. This is something like we have a conference hall which is divided in different rooms. In this Hall, where in each room we have different people, all of them talk at the same time. So, the rooms acts as different frequency bands in our analogy. The frequency spread is 30khz and this is 1G. So, each room acts as unique frequency. But the problem with this was that there are not enough conference rooms, meaning not enough frequency spectrum and henceforth poor spectral efficiency. So, a concept of frequency Re-use was introduced where in same frequencies were used for places apart (within a certain set distance).

1. Analog (AMPS-Advanced Mobile Phone System) starts wireless revolution

2. Cooper places first analog phone in 1970, Motorola develops the technology

3. TACS- Total Access Communication System(Europe) and JTACS(Japan) were close relatives

4. System architecture for 1st generation invented and Digital AMPS evolves

All people in same room. If they talk at different times- TDMA

So, the next approach was TDMA, that is Time Division Multiple Access. In our analogy, the speakers here speak in the same room. but all speak at different times. Also, we across a concept called VoCoders, which helps take data rate down and squeeze in 3 times more calls than what it was in Analog. Now, here in TDMA, the spread is across 30Khz frequency again. This gives a better spectral efficiency. So, using Vocoders and time slicing, things become better. So, this was approximately 2G. Then. further things were expanded. GSM:2G came into existence. The bandwidth allocation was at 200 khz instead of the 30 Khz. So, 8 channels were there per radio channel. But then. the need for more capacity was felt. So, more cell splitting required. But, each of the smaller cells require the same equipment investment and physical space as their counterparts. This is an expensive solution. 1. In the late 70s, TDMA comes into existence, later evolves into IS-136

2. It is then deployed by AT & T, and US Cellular, then by Roger Wireless in Canada

3. Both of them together upgrade it to GSM

4. In 1980s, rapid growth in analog in Europe,but notion of unification coming in. 

5. In 1989, responsibility for GSM passed to European Telecommunication system Institute

6. in 1991, first Commercial Service startswith max 9.6 kbps data rate. 

That may just overflow the CDMA capacity in my analogy

Next came, Spread Spectrum Technique- CDMA, where in different spectrum were spread by a code into a larger spectrum upto the bandwidth of 1.25 to 5 Mhz. All users here share the same frequency and communicate at the same time. It is like throwing a bunch of people at the same time in a swimming pool. So, no personal frequency at a time, but a personal code. In our analogy, it is like speaking different language, all people at the same time. Now the advantage with this was that it needed only 5db SNR to have a successful conversation with respect to the 17db that was required earlier. This was because of the error correction techniques encoded. But again, even in CDMA, without power control, in our analogy, it would be a situation where if one speaker speaks loudly, the other too have to raise their voices to be heard and this would create chaos and noise. The maximum capacity would happen when each cellular phone transmits at the minimum power level. There are a lot of other terminologies and the wireless communication world moved ahead extensively since, that some even say that it has reached a point of saturation now. Will cover all that in the next blog may be. 

 

Closing Notes on Data Services Evolution - Part 1 :

1. There was need for data transmission to POTS(Plain Old Telephone Service), ISDN, Packet Switched Circuit.

2. With 8 time slots for each TDMA frame,GSM only provided circuit switched data at low speeds.

3. GPRS (General Packet Radio Service) came into being, which was designed to overload onto GSM N/W with large-scale reuse of the physical layer. 

4. In this, multiple slots were dynamically allotted and could achieve higher throughput and better efficiency

5. But, multiple time slots implied eating up voice calls. So, Enhanced GPRS (EGPRS) came into existence. 

6. EGPRS, or EDGE(Enhanced Data Rates For GSM) used higher order modulation (8-PSK), could carry higher data speeds

7. First EDGE commercial was deployed in 2003. 

8. All of this thoguh being low cost, was of medium capacity and low speeds. Not se great on data and so, slowly 3G/WCDMA evolved, which we'll talk on later.

P.S.: Again, feel free to share your views, whatever they may be.

The Age of Machine-to-Machine Communication

Skynet

Ever Imagined a world where your Washing Machine communicates with your Home Sound System and adjusts the noise level of the washer accordingly? Ever Imagined a world where your car interacts with your rice cooker and sends signals to automatically turn the shit on, a world where your thermostat interacts with your door and adjusts the temperature sensing your arrival as per your needs? Well, whatever you can imagine of, the most bizarre thing you can dream of in the world of Technology, is today being made possible, being converted to reality!! And, most of us have now become familiar with that technical term thats making it all happen- IoE (Internet of Everything) or Internet of Things as some like to call it. The Internet of Things is an extremely wide field, that is revolutionizing the way we live, and the entire wireless communication industry. In this blog though, I will touch only a small portion(which in itself is another world) of the IoT- M2M: that is Machine-to-Machine Communication. Check out this video to see a day in the World of IoT

Delving around the Off-shores of M2M

In the 'Terminator', Skynet, a Global Intelligent Machine with Sensors everywhere tries to destroy mankind. Or take the 'Iron Man 3' for an analogy,  in which our hero Tony Stark builds an advanced mechanism where-in too many Iron Mans(ya, that may not be absolutely correct to say) come into existence each one communicating with each other, trying to save the world. Or lets get down the local lane may be, take for example Rajnikanth's 'Robot' where in the climax scene different bots start communicating with each other and forming different structures. In our analysis, it doesn't really matter whether who is good or bad- whats important is the use of sensors and communication across machines. These were simply examples of 'machines'. Well, machine-to-machine communication is not about, or should I say, not just about such machines! It deals with even the smallest of devices you see around. Then what is it? Let us give it a try to understand Machine-to-Machine Communication from the scratch. As the name suggests- Machine-to-Machine (M2M) communication is a form of data communication that involves one or more entities that do not necessarily require human interaction or intervention in the process of communication. M2M is also named as Machine Type Communication (MTC) in 3GPP (Telecommunications Standard Specification).

Advanced Smart City Framework. Source: Google

As we can see above, it is an extremely elaborate pictorial representation of the advanced Smart Cities that involve Smart Grids, Satellite Communication, Travel, Safety etc and all is made possible by Machine-2-Machine Communication whereby, through a system of sensors and actuators, and a highly sophisticated data processing and storage centre, the information is finally dissipated via WLAN and other relevant broadband technologies. Ok so, how does the entire shit work? I mean, all this sounds pretty cool, the world being made automatic, and sensory, the things getting connected to each other, each device having its own IP address, life becoming technically advanced, but then this question keeps hovering- HOW!!! Lets give it a shot to try and answer that in as short as possible:

Sensors and Communication protocols- yes, they come across the first and foremost requirements for M2M. Lets explain the enitre process with an example. From those mentioned above and from many infinite possible scenarios, I chose a simple scenario where-in the  car sends a signal to the Air-conditioner in the room to turn the temperature on to an optimum level given the distance left for the owner to arrive home. So, the Air Conditioner has some inbuilt Wi-fi chip within it that takes care of the reception of the signals. The Car has a sensor that given the distance left to reach the target place- in this example which is home and on the basis of machine learning given the speed variation patterns of the driver(owner), judges the approximate time to reach home. Then, when a certain threshold of arrival is crossed over, the sensors send a signal to the Air-conditioner in the room to  turn on and set to the desired level according to the climatic conditons. This way, the extra time that the Air-Conditioner takes to set up the proper weather inside, is saved. This is a very basic example of M2M, and should not be confused with the infinite possibilities it offers, and the immense processing involved in most cases including support from Cloud services, servers, advanced wireless communication technologies, Gateways etc. Shall take a delve down each one in separate blogs.

The Transforming Market of Wireless Communication and Devices

So, what does the above example need, whats the cost and how is the industry behaving like? 

The numbers are staggering! And trust me on this, like the population of India is only a rough estimate of sorts and involves a huge extrapolation, the same is with this market. It is expected that around 20 billion connected devices is going to come into existence by 2020. Holy Moly! Now you compare that number with the existing mobile subscribers- around some 5 billion. So, the industry that has been evolving since years, has given birth to giants like Vodafone, Qualcomm, Samsung- yes we all- the entire telecommunication industry and the chip world, is on the verge of a turn-around. And, its not a days process- like Rome. Its happening already!  Check out some of the amazing examples from the world's leading industries:

1. GE Jet engines have been there for decades I guess. But its evolving rapidly in the past few years with the new variety having sensors that send the entire information related to the plane and the engine to the servers including the pressure, landing time, required servicing etc.

2. GM have built an embedded automatically notifying system in their cars that in case of accidents, sends messages across to ambulances and hospitals.

3. Google, which recently bought 'Nest' has put in billions of dollars in home automation, like many other giants.

4. Cisco has already made the Smart Parking implement in some parts of US

5. Cities like Barcelona have been declared as 'Smart Cities' with everything connected- from transportation to medical facilities

6. Startups evolving on this industry like one involving a friend of mine, whose startup is based on IoT for Transportation with automatic carrier vehicle guide, track and stop mechanism.

This is an extremely exhaustive line-up but I will cu it to this space for now. This was just relating to the device manufacturers. With this, the chip manufacturing world is also to see a big change. For example, Qualcomm plans to design special WI-Fi chips for the purpose. And why not! An additional such chip would cost around only a few dollars inside the AC example that we discussed earlier. And, if spending that much gives the AC manufacturer a lable of  'Smart AC' and allows him to know about the complete working conditions form anywhere, the log tables, analysis, then why not! The opportunities are massive. If you need something to be automated, to be connected, you need to design relevant wireless chips. Then, the need to have a GUI arises, a display and there in comes the DSP chip. Todays world demands high resolution in everything and so the technical demands shoot up. A big market space, henceforth!

This is just the forecast for Consumer electronics alone! Source: Machina Research

Finally, the advanced LTE-A for M2M:

Long Term Evolution's new release- LTE-Advanced is meant for solving a lot of connectivity issues for the Machine Type Communication. As 3GPP defines it, this release, Rel-13 has a lot of improved specifications for the M2M. A detail analysis on this would also require another article. So sometime later. In LTE-Advanced focus is on higher capacity: The driving force to further develop LTE towards LTE–A - LTE Release10 was to provide higher bitrates in a cost efficient way and, at the
same time, completely fulfil the requirements set by ITU for IMT Advanced, also referred to as 4G: a) Increased peak data rate,
b) DL 3 Gbps, UL 1.5 Gbps Higher spectral efficiency, from a maximum of 16bps/Hz in R8 to 30 bps/Hz in R10.
c) Increased number of simultaneously active subscribers.
d) Improved performance at cell edges, e.g. for DL 2x2 MIMO at least 2.40 bps/Hz/cell.
The main goal of LTEAdvanced is to provide the IMT-Advanced functionality while retaining backward compatibility with current LTE user equipment that subscribers own. When a large number of machine-to-machine (M2M) devices are trying to access the network simultaneously, it leads to a low random access (RA) successful rate and high congestion problem, which may cause the waste of radio resources, packet loss, latency, extra power consumption, and the worst, M2M service error. With a potential market of probably 50 million connected devices, M2M offers tremendous opportunities as well as unique challenges.  Again, how did all this happen and the transformation of the entire market from 1G to 4G, or should I say 5G, we'll cover that in the next blog may be.

The most important thing that concerns everyone in this regard in security. A lot of Wireless Mesh Protocols like CBM-HWMP, are though good enough but need lots of improvement. This entire new technical world that involves the cloud and the IoT, is facing this very major problem to tackle. But then again, M2M, given the immense scope it has, in different fields like, Healthcare, Vehicle-2-Vehicle Communication, Bridge Health Monitoring, Transportation and Logistics, Security and all this in real-time, advancements in all fields are at a rapid progress. The world is transforming, the industry is revolutionizing.

P.S: Feel free to share all your views. This afterall is not coming from an established technical industrialist, but just from another student in an engineering college trying to get that Btech degree in Electronics Engineering :P