DTRI - Blog by dtri

A Journey of Putting A Noble Cause To Action

Fri, 08 Dec 2023 07:10:31 +0000

Introduction

Snippets from our first journey towards a noble cause of upskilling rural engineering talents.

6 Months * 5 Rural Engineering Colleges * 250+ written tests * 60+ 1 on 1 interviews * 23 talents short listed * 17 Trained On Technical & Soft skills * 100% Placement

Any CSR funds to support skill development of rural engineering talents in electronics product development may reach out to us at connect@dtri.in.

Decision Factor
During April 2022, Kiran from DTRI called upon us (Geethesh and Narayanaswamy) and put forth his idea of starting an embedded design course for students of rural engineering colleges. Also, as a startup entrepreneur, with 15+ years of solid industrial experience in multinational giants like Qualcom and Intel he was upbeat in contributing to society by means of upskilling the rural talents.
Since myself and Narayan started our entrepreneurship journey in 2012 in similar training venture called Mysore Embedded Technology Institute where we even delivered our training at NIT Nagaland, Ganpath university, Ahmedabad, Agra, Sholapur apart from most of the Engineering colleges in and around Mysore including Rural engineering colleges before pivoting to an IoT product and services company. With this experience, before restarting the training we had a few questions for Kiran and I am recording whatever I remember here.
G&N: who will pay for expenses? Let’s forget the profit for this moment.
Kiran: We will get it from the companies who hire them.
G&N: That amount we will get after we successfully place them, till then who will bear the expenses?
Kiran: I will take care of that
G&N: The cost centers for this venture will be Subject Matter Expert( SME ) charges, Assistant trainers charges, Rent for the place that can accommodate at least 20, Microcontroller training board & accessories charges, basic amenities like water, EB charges, marketing visit charges, Selection test material preparation and printing charges, Selection process visit charges, course material preparation and print charges, administrative and miscellaneous charges and this would come up to ~3 Lakh per month. At present we can defer our SME charges, but still you would be requiring a minimum of ~100,000/- per month.
Kiran: Ok I am ready to bear it.
G&N: From my previous experience, in seminars conducted in rural engineering colleges, I used to get more questions but with all due respect, training rural engineering students will be a herculean task because of language, cultural and knowledge barriers.
Kiran: Since the admission for the colleges are through CET exams, there also we can find good talents who are still trainable. We will select for this training by doing our own test.
G&N: We will take up training delivery but who will work towards placing them so that we will get back our deferred investment.
Kiran: I will take that responsibility
G&N: There is already some news about recession going around, what if we are not able to place all of them if hiring freezes.
Kiran: We have to take the risk and I am ready for it
Appreciating his enterprising qualities and his courage to put skin in the game, we jumped in for an association.
Journey Begins
Next step, Kiran started charting plans to approach the colleges, scheduling our presentation, conducting entrance tests for students for the course and our enrollment yatra started. We visited govt engineering colleges starting from Chamarajanagar, KR Pet, Virajpet, Haveri and private colleges like Bahubali College of Engineering, Shravanabelagola and GSSS women's engineering college, Mysore. This Yatra happened from May to July 2022 .The selection process involved a written test with C language + electronics timed MCQ’s followed by personal interview and listing for selection, all these to happen when we visit the campus. In a nutshell, we conducted written tests for around 250+, one on one interviews for 60+ and selected 23 candidates for a free embedded design skill development program.
Start of Upskilling Program
From Aug 22 the training program on “Embedded Systems Design” started for the first batch of 23 hand picked engineers from five rural engineering colleges and out of it two were from women’s college.
The training program was done in collaboration of three entities DTRI front ending the entire training & placement effort, METI delivering the training and SJCE STEP providing space and facilities to conduct the training in SJCE campus.
The training was delivered free of cost and as a prior information and agreement. Students arranged for their stay and food on their own. We knew that for some of them it was a financial burden but that’s the best we could do with our financial condition.
As announced earlier the training was very regimental in nature and there was a final round of selection after three weeks. Only 17 could make it to the final round of selection. From Monday to Saturday ,full day training with lunch and tea breaks.

The regimental training pattern was like this
C programming
Electronics basics
Embedded programming
Daily assignments to do after they go back home
Soft Skills like communication etiquettes (both verbal and written)
Weekly mock interviews
Daily online tests
Weekly Tests
Exposure to corporate systems
English & Confidence
With all these we found that due to their background they were struggling to speak in English and their confidence used to go down even if they knew the concept and answer. Then based on feedback and assessment we arranged a spoken English course from a reputable professional and in the next three weeks we noticed a wonderful change happening with them in their confidence level.
Hiring Client
Meanwhile, within a few weeks of closure of this program, A reputed automotive specialized services company from Bangalore, showed its interest in taking up trained engineers and wanted to introduce automotive concepts as a part of the course. Along with embedded training there was additional training in a week and tests, assignments were conducted including new topics.
Additional Concepts & Scholarship
Post completion of automotive training, conducted one special test on automotive lessons and hiring client announced a scholarship to the students who qualified their tests. In that process few of the students got qualified and started getting paid.

This was a confidence changing point for our team also about the incremental learning appetite the students had developed over the last few weeks. In the beginning students were complaining about shortage of time with loads of assignments in the designed topics, everyone was stressed out and as weeks passed by, as a normal human behavior they started to acclimatize to the new learning environment and by the course coming to an end, even when unplanned subjects were introduced, I will not tell that they aligned very fast rather I would put it as the latency to adapt and learn was quite short.
Skills learnt and 100% Placement
By end of the program, the students were empowered with following skills : In the technical gambit, C Programming, Embedded C programming, Electronic circuit reading and analysis, PCB study, Electronic component data sheet interpretation, Automotive concepts . In the soft skills gambit each of them climbed one or two steps in English communication (both spoken and written), confidence level, interpersonal skills, responsibility, persuasion, collaboration, diligence, time management etc.
By the end of the program, our client put up an offer to hire all of the 17 who successfully completed the course. Our first journey towards a noble cause can be summarized pictorially as depicted below.

Conclusion

This was even a good learning experience for our team also about the high expectation candidates hold after a 4 months course in comparison to their graduation that spans to 4 years. With this experience we are willing to take up similar programs, but the biggest challenge is Rural students cannot afford to pay the fees that this course budgets at and without fees we will not be able to run the courses.

During 2023, we put an effort to repeat this feat but due to financial challenges we had to put it on hold. In this regard, if a corporate shows interest in funding this program through their CSR initiative, DTRI would certainly be interested in continuing to work for the cause.

Catering to Diverse Learning Styles: "Enhancing Training Sessions for Optimal Learning"

Mon, 31 Jul 2023 07:41:33 +0000

Introduction

In any learning environment, understanding the diverse learning styles of participants is crucial for designing effective training sessions. People have different preferences when it comes to acquiring knowledge and skills, and tailoring training programs to align with these learning styles can significantly enhance the learning experience and improve outcomes. This article explores the concept of learning styles and provides insights into designing training sessions that cater to various learning preferences.

Understanding Learning Styles

Learning styles refer to the different ways individuals perceive, process, and retain information. Although various learning style models exist, one commonly used framework is the VARK model, which categorizes learners into four main styles: Visual, Auditory, Reading/Writing, and Kinaesthetic.

Visual Learners: Visual learners absorb information best through visual aids such as images, diagrams, charts, and videos. They prefer seeing information presented in a clear and organized manner.
Auditory Learners: Auditory learners excel in understanding and retaining information through sound. They prefer listening to lectures, discussions, and audio recordings.
Reading/Writing Learners: Reading/writing learners thrive when information is presented through written or textual formats. They enjoy reading materials, taking notes, and engaging in written exercises.
Kinaesthetic Learners: Kinaesthetic learners learn best through hands-on experiences and physical activities. They prefer engaging in practical tasks, demonstrations, and interactive exercises.

Designing Training Sessions for Different Learning Styles

Visual Learners:

a) Utilize visual aids: Incorporate visual elements such as slides, infographics, and diagrams to present information. Use colour coding and clear formatting to enhance understanding.
b) Visual demonstrations: Provide visual demonstrations or videos to showcase practical tasks or processes. This allows visual learners to observe and learn from the visual cues.
c) Mind mapping and concept mapping: Use mind maps or concept maps to visually organize complex information and interrelationships. This helps visual learners see the bigger picture and make connections.

Auditory Learners:

a) Engage in discussions and group activities: Create opportunities for auditory learners to participate in discussions, group exercises, and role plays. Encourage active listening and verbal communication to reinforce learning.
b) Lecture with audio elements: Combine lectures with audio elements such as sound clips, recorded interviews, or podcasts. This provides auditory learners with the opportunity to absorb information through hearing.
c) Repeat and summarize key points: Repeating and summarizing important concepts throughout the training session helps reinforce auditory learners' understanding and retention of information.

Reading/Writing Learners:

a) Provide written materials: Offer handouts, manuals, or textbooks that allow reading/writing learners to engage with the material at their own pace. Encourage note-taking and reflective writing to aid comprehension and retention.
b) Incorporate written exercises: Include activities such as quizzes, case studies, or written assignments that allow reading/writing learners to process and articulate their understanding of the content.
c) Provide access to additional resources: Share relevant articles, blog posts, or e-books to supplement the training materials. Reading/writing learners often appreciate having additional reference materials to deepen their knowledge.

Kinaesthetic Learners:

a) Hands-on activities: Incorporate interactive exercises, simulations, or role plays that involve physical movement and practical application. This enables kinaesthetic learners to actively engage with the material.
b) Real-life examples and scenarios: Provide real-life examples and scenarios that allow kinaesthetic learners to relate the training content to their own experiences. This enhances their understanding and retention.
c) Use props and manipulatives: Integrate physical objects, props, or manipulatives that kinaesthetic learners can touch, handle, or manipulate during the training session. This tactile engagement aids their learning process.

Conclusion

Designing training sessions that align with different learning styles is a key factor in promoting effective learning experiences. By considering the preferences of visual, auditory, reading/writing, and kinaesthetic learners, trainers can create an inclusive and engaging environment that caters to a wide range of participants. Incorporating visual aids, interactive activities, written materials, and hands-on experiences can enhance comprehension, retention, and overall learning outcomes. Remember, a diverse and tailored approach to training ensures that all learners can thrive and succeed.

Chandrayaan 3: How does it Communicate with us?

Sun, 30 Jul 2023 18:04:45 +0000

Chandrayaan-3 is few weeks away before landing on the moon. At the time of this blog publication, the launcher has fully left the earth’s orbit and will be injected into Lunar orbit on Aug 1, 2023, as per the plan. In this blog let us look at the communication system that connects various parts of the mission.

Officially called Chandrayaan-3 or launch vehicle mark-3 on the 4th operational mission (LVM3-M4) on the lunar mission. At a high level, the communication system can be categorized into 2 parts.

Communication during the journey from source (earth) to destination (moon)
Communication after reaching the destination (moon)

Figure 1 shows the communication between ground stations and the launch vehicle during the journey to the moon.

FIGURE-1: Communication system among ground stations, satellite and LVM3-M4

ISRO Telemetry, Tracking and Command Network (ISTRAC) is the center of this communication system. ISTRAC establishes constant and continuous communication with Sriharikota (launch site) and the tracking center in Byalalu which is part of the Indian Deep Space Network (IDSN). The 3 systems are not co-located. Hence communication among these happens through the Indian National Satellite System (INSAT) which is a series of geostationary satellites utilized for such communication purposes. Figure 1 shows three ground stations while the telemetry, tracking, and command (TTC) happens through numerous such ground stations spread across the world.

Figure 2 shows the communication system when the integrated module comprising of lander, rover, and propulsion module have reached their respective positions on and around the moon.

FIGURE-2: Communication system among ground, orbit and moon-based systems

Let us start from the rover. Rover which moves on the moon’s surface can communicate only with the lander. The Lander module soft lands on a specified site on the moon surface and deploys the rover. Both these modules were carried up to the final 100km circular polar moon’s orbit by a propulsion module. The propulsion module with its job done of releasing the lander module (and rover) will stay in the lunar orbit and make future discoveries as per the design.

Lander can communicate both with the rover and directly to IDSN (ground station). Chandrayaan-2 orbiter is still circling the moon. Chandrayaan-3 lander has been designed to communicate with this Chandrayaan-2 orbiter. This will act as a backup link in case the communication between the lander and IDSN breaks down. The propulsion module collects important data from space through its numerous sensors and transmit to IDSN. TTC represents command/control operation and other communication bands are for talking to ground station are for sending data like high-resolution images from the moon.

At the baseband level, well known modulation, coding, and multiple access schemes are used as tabulated in Table 1.

TABLE 1: Modulation, Coding and Multiple Access Schemes

Did you know? Flow charts are not limited to Software alone!

Mon, 10 Jul 2023 20:18:59 +0000

Flowcharts are very helpful tool to visualize a process, make a decision, or understand the flow of data. A flowchart is a diagram that shows the steps involved in a process or algorithm. Flowcharts are used to visualize and communicate complex processes in a clear and easy-to-understand way. They can also be used to document processes, identify potential problems, and improve efficiency. Flowcharts are written using boxes and arrows. The boxes are of different shapes which represent steps in the process. The arrows represent the flow of information between steps. The different types of boxes commonly used in flowcharts are:

Process step: A process step is a rectangular box that represents a single step in the process.
Decision: A decision box is a diamond shaped box that represents a point in the process where a decision must be made.
Input & Output: A parallelogram shaped box represents both data or information that is entered into the process and data that is produced as output from the process.
Terminator: A pill shaped box that is used to represent the start and end of the flowchart.

Here are some of the different types of flowcharts that are used:

Process flowchart: This type of flowchart shows the steps involved in a process. It is often used to document a process or to improve a process.
Decision flowchart: This type of flowchart shows the steps involved in making a decision. It is often used to help people make decisions or to document the decision-making process.
Data flow diagram: This type of flowchart shows the flow of data through a system. It is often used to document a system or to improve a system.

Flowcharts can be a helpful way to visualize a process, make a decision, or understand the flow of data.

Flowcharts can be used to represent a wide variety of processes, such as:

Business processes: Flowcharts can be used to document business processes, such as the order fulfillment process or the customer service process.
Software development processes: Flowcharts can be used to document software development processes, such as the requirements gathering process or the testing process.
Scientific research processes: Flowcharts can be used to document scientific research processes, such as the experimental design process or the data analysis process.

Here are some of the benefits of using flowcharts:

Improved communication: Flowcharts can help to improve communication by providing a visual representation of a process. This can be helpful for explaining processes to others, such as new employees or customers.
Increased efficiency: Flowcharts can help to identify inefficiencies in processes and make it easier to recommend improvements. This will increase efficiency and productivity.
Reduced errors: Flowcharts can help to reduce errors by providing a clear and structured way to document processes. This can help to ensure that steps are not skipped or repeated incorrectly.
Improved quality: Flowcharts can help to improve the quality of products or services by ensuring that processes are followed correctly. This can lead to fewer defects and a higher level of customer satisfaction.

Overall, flowchart is a valuable tool that can be used to improve communication, efficiency and quality of a process, and productivity.

Example flowchart for making a cup of filter coffee.

The Need For Ethics In The Education Industry

Tue, 04 Jul 2023 05:54:32 +0000

You cannot escape the all-encompassing embrace of Big tech. It will hug you tight tomorrow if not today. We live in its shadow, like it or not. You might as well smile under its clutches. It’s 2023 and there is no business on Earth that hasn’t been internet-ified. And why not? We live in a world of extreme pace. Entrepreneurs, investors, engineers and your neighbor are looking for scalable solutions that can make a quick buck. “There is always money to be made in food, pharma and education”. I don’t know who said it but someone did. The “Education industry” is an estimated six trillion-dollar market. The brick and mortar school to higher education sector does not concern us in this blog, but we will look into the lucrative and shady world of online education. This sector caters professional courses for graduates all the way down to primary tutoring. I know, the term “online primary tutoring” sounds very murky without exaggeration. To even build a scalable, profitable, 50x-returns-for-VCs kind of business, you are not going to get there without some serious sales and marketing operations. And that is the first problem we will discuss.

1. Selling to kids.

In some countries,it is illegal to advertise to children below a certain age. Regardless of the legal status, the practice is undoubtedly an extremely grey area bordering on unethical. So, what does it say about the much-touted unicorns that market to kids in India, when they not only make ridiculous and insane claims such as a certain Wolf Gupta aged 13 that earns in crores working at Google as an

AI researcher, but going so far as to paying shady companies to acquire cell phone numbers of underaged children?

In an ideal world, the people behind such antics would be finding it tough staying out of the courts. But today they are merely on the receiving end of mild internet ridicule, some of which ironically invites the ire of the culprits themselves and some comical defamation suits.

2. Quality of education.

Continuing in the vein of my previous point, if you dig into the numbers of the top Ed-techs in the country, you would find the top expense to be “Advertising and promotional” expenses. Mind you, this covers only fees paid to celebrities to be ridiculous on TV and big highway-side hoardings and such. We’re not even talking about sales, marketing and legal costs.

Only a paltry amount goes into actually creating quality, well-researched content and remunerating trainer fees. Not to mention, most school level tutors have been well known to be just, pardon my French, “picked off the streets”.

On the opposite end of the spectrum, for professional courses, “celebrity tutors” that have a well-established personal brand, auction themselves off for multiples of crores.

How then can the big guys assure us of quality education when their process is so marketing-heavy?

3. Tall claims and employment data.

I do not want to refer to the depressing oft-quoted survey and its “How many Indian graduate engineers are employable?” and “How many Indian graduate engineers can code?” numbers.

It is no doubt clear that our universities and policies are failing the youth. This does open up a space for the private edtech sector to right some wrongs. But amidst intense competition and plenty rival businesses, we see tall claims of guaranteed placements and promised packages.

But when it comes to raw numbers, the data is worrying. A survey by LocalCircles across 323 districts from April 1 to May 31, 2022, with around 27,000 respondents found that at least 69 per cent of respondents faced infrastructural issues and deprivation of vital services required while attending online classes, as cited by TheLogicalIndian.

The survey also found that nine per cent of consumers had infrastructural problems, 19 per cent did not like teaching staff effectiveness, and 10 per cent experienced refund-related problems.

This, of course, doesn’t mean that all edtechs are out to get you and your money. This is a wakeup call to the industry as a whole to stand up and take responsibility, adopt ethical practices and internal guidelines. Learn from past mistakes and communicate honestly to the customer.

Youngsters have to be especially careful when choosing organizations to help them in skilling up and boosting their careers. Go through the website, talk to the trainers (and not just the sales guys), assess the capabilities of the training organization and make educated choices.

Juhi vs. 5G

Wed, 01 Feb 2023 19:34:12 +0000

It is natural for us to take notice when a celebrity raises a topic of global interest and takes the matter to court. This is about Indian actress Juhi Chawla taking 5G deployment in India to Delhi High Court. As of publishing this article, the court has dismissed the petition and the actress is no longer against 5G deployment.

5G trials will start in India soon and it merits to look into the concerns highlighted in the petition and the advantages of 5G in Indian context. Many well-known online web portals have highlighted key points from the 5000-page petition.

I have spent considerable amount of my career in top wireless organizations like Qualcomm and Intel before founding DTRI, a wireless education company. I base this article from personal experience and the points that I picked up from this case.

Before I address key concerns from the petition, let us review a simplified cellular network as shown in Figure-1. It has 3 major components.

Base station or what is also called as mobile tower or tower
User Equipment (UE) or also called as handset or the mobile phone but could be any thing in IoT context
The invisible wireless communication link which connects the tower and the UE

Figure-1 [pixabay.com]

One of the major concerns raised by the petition is about excessive radiation by the tower and its negative impact on environment. Since the radiation is invisible there is a fear of unknown!

While the cellular network shown above is similar whether it is 5G, 4G, 3G or even 2G, it seems as a society we have accepted all ‘Gs’ except 5G. Today without 4G we have to give up smart phones and all the useful and entertaining applications like Amazon, Netflix, Tiktok and so on. Even a simple phone call with a basic mobile handset requires 2G network. Popular technologies like WIFI, Bluetooth, GPS, all use wireless communication. This implies that the two major components of the network – UE and the wireless communication link is not perceived as a problem by the society.

The concern is about the mobile tower, a 5G tower to be specific. The petition claims that 5G radiation levels are 100 times more than the current cellular radiation levels [1]. 3GPP, which is the specifications body for both 4G and 5G technologies shows no such difference in radiated power from the mobile tower [2]. But things could change with MIMO (multiple antenna technology). Compare the light coming out of an electric bulb and a torch light using two similar AA batteries as shown in Figure-2.

Figure-2 [pixabay.com]

Imagine MIMO to the torch light which focuses energy in a particular direction vs. SISO (single antenna technology) system which is like the bulb emitting dispersed energy. MIMO is part of 4G but in 5G, the signal is much more focused on a particular UE due to massive MIMO. This focused beam energy can be 10 times higher than 4G. This is akin to comparing torch light with a laser pointer as shown in Figure-3.

Figure-3 [pixabay.com]

Does it mean 5G radiations are more dangerous than 4G? This is where regulatory bodies have to step in. Consider the case of FCC, the regulatory agency in USA. FCC has specified ERP (maximum focused radiation in a direction) under Title 47 of CFR for radiating towers. The specifications are based on factors like frequency of operation, height of the tower and the population density in the region. Even though the torch light is more focused than the laser light both have an upper (maximum) limit on brightness. Whether it is 4G or 5G, MIMO or massive MIMO radiation upper limit is not violated as per the law.

The cellular network operators (Example: BSNL, JIO, Airtel) do not operate the base stations with maximum radiated power. Maximum power operation implies network inefficiency and a direct hit on the revenue. A typical 4G LTE network operates at 12% of maximum power for 90% of the time in a 24-hour duration [3]. Thus, a tower which is capable of radiating 100 watts of power is radiating only 12 watts for 90% of the time. Thus, the radiation is not intense and full blast 24/7.

So far, we looked into power radiation. Another concern is about the frequency of operation. 3GPP specifications define 5G deployments below 7GHz (currently <6GHz). This is frequency range-1 of the spectrum and same as 4G technology. Frequency range-2 is specific to 5G and not defined for 4G. In this range the network operation is >24GHz called the milli-meter wave (mmWave) communication as shown in Figure-4.

Figure-4 [www.qualcomm.com]

Milli-meter waves may have led to some fear due to comparison with X-rays which are ionizing and known to damage tissues with prolonged exposure. But this fear is far-fetched since mm Waves are neither close to X-ray frequencies nor ionizing as shown in Figure-5.

Figure-5 [www.bbc.com]

Milli-meter wave signals cannot travel farther (range <1km) in practical cases. The tower and mobile phone have to be in line of sight to overcome environment losses and for effective communication. Thus, mmWave in practical mobile phone communication can happen when the tower and UE are very close to each other. When closer, the tower (also called micro/pico base station) has to radiate power about 100 times lower than the regular huge towers (called macro base stations). MmWave is good for short-range applications like indoor communication. It can be an alternate to WIFI in commercial complexes, apartments, hostels and private networks.

So far, we addressed the power and spectrum perspectives of 5G. If current 5G implementation is almost comparable to 4G then it is the right time to question why 5G?

The fundamental assumption is that 5G is the next version of 4G and that we will switch from 4G phones to 5G phones. For want of faster download speed the cellular communication generations progressed from 2G to 4G. This is not the only reason to move to 5G. Further, mobile phone communication is not the only 5G use case but one of the many use cases. Recent 5G progress is very visible due to new 5G phone release advertisements that we see in media.

Mobile phone as an early 5G use case is due to following major factors:

Mobile phone is a huge market and easy to convince B2C customers to move to 5G than B2B customers. B2C customers in the past progressed from 2G to 3G to 4G with attractive new phones and low-cost data.
Mobile phone market also provides enormous and valuable data to operators to improve 5G network efficiency in general. This data is critical for the 5G stakeholders to move the market towards 5G.
Use cases in 5G are plenty but revenue generation is a challenge. Example: IoT is a big market but fragmented with various vendors and pieces to fit a large puzzle. Entire IoT ecosystem of hardware and software is not standardized. Industrial IoT is a big space to enter but not until B2B customers see RoI for million+ $ investment in 5G.

Above points do not undermine recent advances in autonomous driving, industrial IoT and private networks which in fact are practical use cases of 5G.

Coming back to why 5G it is important to note that 5G is not only about high-speed internet but has 3 focus areas for communication:

Highly-reliable and low delay network (URLLC) for mission critical services
A massive network of low-powered, low-data rate devices (mMTC)
A network offering high speed internet (eMBB)

These 3 focus areas together form the Trimurti of 5G communication as shown in Figure-6.

Figure-6 [www.qualcomm.com]

URLLC (Ultra-Reliable Low Latency Communication)

A URLLC network transfers information with acceptable QoS (>99.9999% reliability) and lowest delay (<1milli-second). The specifications are defined by organizations like 3GPP. An adequate and functional healthcare infrastructure is evident during this pandemic. Government aims to spend crores of rupees in setting up good clinics in remote areas. But recruiting and placing well qualified doctors in those places is a challenge. As per WHO report there are only about 40% of healthcare professionals in rural India which has about 70% of the population. When it comes to specialists this %age drops further [4]. Pre-pandemic, tele-medicine was not preferred both by doctors and patients alike due to obvious reasons. During this pandemic life changed. Both parties are now open to tele-medicine. This can be a boon for patients who are not living in cities and yet can consult with best doctors located anywhere in India [5]. Today’s tele-consultation is limited to audio/video calls. This opens up more possibilities for entrepreneurs in creating new products in advanced medical procedures like robotic surgery [6],[7]. Some hospitals like Apollo are already into robotic surgery. Robotic surgery requires high precision. This mandates that the network is ultra-reliable (lowest errors) and offers least delay, features which are part of 5G technology.

mMTC (massive Machine Type Communication)

Interconnecting a massive number of low power consuming (Example: battery operated devices) in a IoT system is another focus area of 5G. In this scenario the devices do not demand high speed internet or need large data upload/downloads. Consider the case of smart meters for recording home power consumption and billing [8]. Smart meters improve efficiency for power supply companies (Example: BESCOM in Bengaluru). It also reduces bill amount for consumers. Current smart meters use GSM technology. Indian government is on a mission to convert existing analog/ digital meters to smart meters across India. The push is to move from GSM to 4G NB-IoT technology. These meters can finally adopt robust and secure communication technology like 5G. At present there are 10+ Indian states where smart metering is either implemented or in pilot stages [9].

eMBB (enhanced Mobile Broad Band)

High-speed internet is a need for entertainment, gaming and shopping applications. During pandemic online education became a necessity. Educational gap is noticed due to digital divide and the resulting disadvantage to rural schools. There are various for-profit organizations who have built a fortune over online education. To overcome the educational gaps there are many not-for-profit organizations. Example: eVidyaloka (www.evidyaloka.org) a NPO offers live teaching to students in rural schools. This requires a good and stable internet connection. From past few years, service providers like BSNL, JIO and Airtel provide high-speed connectivity to remote areas. I hope education takes precedence over digital and geographical divide.

Concluding…

Killing someone with a kitchen knife is a real possibility but that does not mean government bans selling and using knives. If 5G or any electromagnetic radiation is found to be detrimental to flora, fauna and humans then we researchers, engineers and the government have further work to do. Let us put a sign work in progress and get back to our drawing board.

References

[1] https://gadgets.ndtv.com/telecom/news/juhi-chawla-5g-case-lawsuit-dismissed-fine-penalty-rs-20-lakh-delhi-high-court-2456540

[2] www.3gpp.org, Specification #: 37.145-2

[3] Measurements of downlink power level distributions in LTE networks, IEEE Xplore

[4] https://www.who.int/hrh/resources/16058health_workforce_India.pdf

[5] https://www.news18.com/news/india/telemedicine-services-become-boon-in-chhattisgarhs-naxal-affected-dantewada-3831668.html

[6] https://gadgets.ndtv.com/science/features/robot-assisted-surgeries-important-india-covid-19-pandemic-5g-surgeon-2268786

[7] https://www.businesstoday.in/sectors/pharma/indias-first-general-robotic-surgery-system-to-hit-markets-in-4-6-months/story/432488.html

[8] https://energy.economictimes.indiatimes.com/news/power/eesl-announces-installation-of-10-lakh-smart-meters-across-india/74288317

[9] https://www.smart-energy.com/industry-sectors/smart-meters/2-34-million-smart-prepaid-electricity-meters-for-indias-bihar-state/

WHY 6G?

Wed, 01 Feb 2023 19:15:28 +0000

We are in 2020, of course a disastrous year, but yeah amidst all these, 2020 was highly regarded from a decade. Even Abdul Kalam dreamed of a revolutionary 2020 which could bring a huge change in the field of science and technology. He actually wrote his ideas and imaginations about the upcoming technologies in the book “India 2020“.

One huge step ahead in the field of communication technology in 2020, was the launch of fifth generation networks [5G] all over the globe.

But at the same time, the study of possibilities of 6G communication has already begun.

We haven’t even experienced the quality or efficiency of 5G or in other words, 5G is yet to make its way to every homes, besides it has various advanced technology imbibed in it, then why do we need to think of 6G?…. This post might give you some answers.

Before thinking of 6G, let us just know basically what 5G will bring?

Primarily 5G brings as we all know very high data rate. With the growing demand, increase in the number of internet users, as applications of internet got wider, it was essential to have high data rate in terms of Tbps [enhanced Mobile Broad Band]. Along with that, the number of smart devices have increased drastically. Most of them requires connectivity [Massive Machine Type Communication]; 5G provides large connectivity too. Along with them, decrement in latency is one more additional feature. IoT is now possibility due to 5G.

Image Courtesy: ZDnet

The above image just depicts various applications of 5G because of the features it provides.

It already covers the dream technology of many. Then why 6G?.

We all know, technology doesn’t take birth in a day or two, it is like an evolution [ did you know LTE in 4G actually means Long Term Evolution?]. Lots of research and experimentation leads to one fine technology which we could enjoy. With the view point of what may be the future, the talks of 6G has begun. It is like when we had no mobile phones, the invention of mobile phone seemed like that is the greatest thing ever to be invented, seemed like it is enough for future. But look at the mobiles available now. It has transformed from huge box sized phones to ultra-thin smart phones. The smart phones are becoming more and more smart every month. Every month, a new phone will be released with improved features. This itself indicates, for the current smarter human race, nothing would suffice. The demand keeps on growing. That is why, despite having a superb 5G technology, the theoretical research about 6G has already started. 6G is expected roll out in 2030. Statistically and technically let us see why 6G?

The above picture shows the global traffic volume. In 2020, it is expected to be 62 Exabytes/Month. 1 Exabyte = 1000 Terra bytes = 1000000 Gigabytes [GB]. Just think how huge it is already. But looking at the future, it wouldn’t be constant as generations grow smarter with new smart devices, it is expected to grow exponentially to reach 5016 EB/month. Clearly none of the current technology nor 5G could bear that. thus there is a requirement for new technology.

Image Courtesy:arxiv.org

This picture depicts the traffic volume per subscription /month vs years. What data plan you have for your mobile, may be 1-2GB/day. That’s like 50 GB/month. That is the traffic volume for your mobile. Considering all the devices, the traffic volume per subscription is meager 5.3 GB/month in 2020. Obviously, the number of devices definitely would be increase. With the introduction of IOT, smart homes, smart cars, there would be a spike in the increment. Thus, the data consumption. Graph says it would be 257.1 GB/subscription which is too huge and beyond the scope of 5G. Hence 5G is expected to reach its limit in 2030. Plus, various new technologies like AI, 3D mapping, VR, AR, autonomous vehicles, smart wearable et cetera requires many features like high data rate per connectivity, ultra-low latency, capability of handling massive data and they are expected in 6th gen. I will post about these technologies in subsequent posts.

Image Courtesy:arxiv.org

The above picture just gives an idea how massive the connectivity grows!!!

Image Courtesy:3G4GBlog

The above picture shows what are the limitations of 5G which could be overcome by 6G. Conclusively, it is not that 5G is inefficient, it is just that 6G becomes inevitable in future.

SAMPLING RATE IN LTE and 5G-NR BASEBAND SYSTEMS

Mon, 30 Jan 2023 17:34:08 +0000

This article was published in IEEE Communication Society Bangalore India Newsletter, Issue 9, June 2021

It is a common knowledge for LTE practitioners that for a baseband signal bandwidth (BW) of 20MHz the minimum sampling rate for converting this signal to digital domain is 30.72MHz. This number of 30.72MHz appears in 3GPP LTE specifications document, for example in TS 36.101.

The sampling rate of 30.72MHz is not intuitive and there are 2 questions which may arise in the mind of first-time reader. Firstly, how can a signal with bandwidth of 20MHz be sampled at 30.72MHz? Does it not violate the fundamental Nyquist sampling theorem which states that sampling rate should be at least twice of signal bandwidth? Secondly, why 30.72MHz and why not use a rather well-rounded number like 30MHz or 40MHz?

The answer to first question is ‘quadrature sampling’. An LTE transceiver is a quadrature system as shown in Figure-1.

Figure-1: Quadrature Transmitter System

The I and Q paths in a quadrature system has its own mixers, filters for processing the signal. An LTE signal of BW 20MHz refers to this quadrature or complex signal bandwidth where individual I and Q paths carry signal within a bandwidth of 10MHz and when combined provide the total 20MHz bandwidth. For each of the paths with 10MHz bandwidth the sampling rate of 30.72MHz very well exceeds (3x) the Nyquist sampling rate.

The second question can be addressed by recalling the LTE transmitter and receiver design which is based on OFDM and how the sub-carriers are generated. Consider the case of OFDM transmitter. The inverse discrete fourier transform (IDFT) or the efficient form of DFT, the inverse fast fourier transform (IFFT) is used to generate multiple sub-carriers. Consider the IDFT equation shown in Equation-1.

Equation-1: IDFT Equation

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Equation-2: Frequency spacing calculation

f_spacing in Equation-2 gives the spacing between 2 neighboring frequencies in a N frequency system. m is an integer which goes from 1 to N which gives the index of each frequency point.

Consider an LTE signal with BW="20MHz" and sub-carrier spacing (SCS) of 15kHz. The number of sub-carriers within 20MHz BW spaced at 15kHz is calculated by dividing the BW by SCS which gives 1333.33 sub-carriers. This value is higher than the actual number of sub carriers specified by 3GPP specifications for LTE (1200 sub-carriers) and 5G-NR (1272 sub carriers). Equation-1 is used to generate these sub-carriers but the actual implementation uses radix-2 FFT where the number of frequency points in FFT should be a power of 2. Thus, to generate 1200 sub-carriers, 2¹¹ FFT is used. This gives the value of N as 2¹¹ or 2048 sub-carriers.

Rearranging Equation-2 as below:

Equation-3: Sampling rate calculation

In OFDM transceiver, identifying f_spacing as SCS which is 15kHz, N="2048" and m="1" (always use 1 since there is no indexing in this context) the sampling rate is calculated to be f_s=30.72MHz which answers the second question.

Equation-3 can be applied to calculate sampling rates for other LTE and 5G-NR BW and SCS cases as shown in Table-1.

SCS (kHz)	BW (MHz)	N	f_s(MHz)
60	100	2048	122.88
15	5	512	7.68
15	40	4096	61.44

Table-1: Sampling rates for different SCS and BW cases