How to Become the Best Interoperability (IOT) Tester


How to Becomethe Best IOT Tester

Field test is challenging!

I was tester for almost 5 years doing 3G and LTE field and lab test. I traveled across the globe to do interoperability testing with operators and network vendors. Each test session was unique and I learned a lot from each of those.

I struggled in the beginning, but as I stated to travel more and more, I began to enjoy those trips. I met a lot of wonderful people in each of those trips.

One thing I learnt from all those trips: There is lot of fun in IOT testing but at the sometime there are challenges.

Are you thinking to start a career as a field test engineer?

In this article I will tell you what it takes to become an awesome tester. If you will follow any of these tips you will be different than the rest.

It does not matter you are new in field test or you are doing it for years, these tips are beneficial for everyone.

Think like a tester

think like a tester

I know what you are thinking. I am a tester. Why I need to think like one.

When I worked in testing teams in telecom companies, I always meet testers who have other opinions about testing.

The goal of a field test engineer is to find bugs in mobile devices or/and in network.

This is the single most reason why we spend days on the field, testing hundreds of test cases.

Though finishing the test scope is important, as a tester your job is to find software, hardware and specification issues. Putting a pass in the test case excel sheet do not make you a great tester.

Your job is to find bugs while testing a test scope.

If everything works, there may be two reasons behind it:

The mobile and network are stable and there is no way to break the system. You are not thinking as a tester. No software is 100% bug free. I am not saying this. One of the most used compilers GCC has thousands of defects. Here is the direct link to GCC buglist.

The sole reason why testers do not find any bug because they are not thinking as testers.

How to think like a tester?

To think like a tester, you always need to assume that the modem or network software is not perfect.

It is always good to check what issues are fixed in the latest release. If you will test more, you are going to find many more bugs in the same functional areas.

This is true for all developers:

We Fix Something = We break something else (I was also a developer and I agree)

Test like a pro

Exploratory testing

Just now we discussed that the goal of testing is to find the bugs in software and hardware.

Now the question comes, how to test better to find more problems in the system?

As a telecom test engineer you get a test scope all the time. Your most important job is to finish the test cases in the scope.

For example, if you get test scope for data throughput, you perform tests to make sure the UE or the network has no throughput issue. They provide the best possible result. You test certain test cases and put pass or fail in the test report beside each test case.

Is that the only way to find bugs in the system?

As I said, testing the full test scope should always be the first priority. But when you finish the test scope or you must try to do something else to find critical bugs in the development phase.

One of the best ways to find issues is by doing exploratory testing. According to Wikipedia

Exploratory testing is an approach to software testing that is concisely described as simultaneous learning, test design and test execution.

Exploratory testing seeks to find out how the software actually works, and to ask questions about how it will handle difficult and easy cases.

The quality of the testing is dependent on the tester’s skill of inventing test cases and finding defects. The more the tester knows about the product and different test methods, the better the testing will be.

In our example, if you are asked to test FTP, ping and UDP data transfer you can try other kind of data transfer methods.

I recall once while testing for throughput issues I tried to test the UE by downloading a file using torrent application. The UE was performing like a champ with FTP, UDP and other protocols. But, the modem was crashing each and every time with torrents.

Try different methods other than the convectional way to find critical problem.

Plan in advance

plan in advance

If you are traveling for a field test session, plan the session well advance. This will clear many things and you will have the exact idea what you are going to do in that trip. No funny surprises and adventures.

Let’s check what usually happens when a test manager or project leader asks a tester to go for a field test session.

  • Your manager/project leader will ask you travel for a test session.
  • You book and approve the itinerary.
  • Travel to the test location and start testing from the test scope.

But here is what an experienced field tester will do to make the test session successful.

  • Test manager or project leader asks the tester for a test session.
  • Book the itinerary and approve it Tester will ask the manager about the scope of the testing.
  • Tester check the test scope and plan the test days in advance Tester gets all the required items, SIM cards, test phones, software, etc. in advance.
  • Make some mock tests to make sure everything is functional.
  • Download and put all required standards and specifications
  • Find out all local attractions and restaurants Travel to test location.
  • Do awesome testing and at the same time enjoy your test.

When your test manager asks you for a field test session, get all the details about the location, who else is traveling with you and most importantly what you are going to test.

The list looks quite big, but it takes only few hours to plan all these and your test session will be 200 to 400% more productive.

By planning everything in advance you will avoid all last minute surprises. I remember once I travelled with a tester who forgot to install correct device driver for the phones. It took him half a day just to identify and fix the problem.

If you have to book a test car for the test session, book that also in advance. Ask the car agency if they can arrange a Power Inverter. You need a power inverter to charge your laptop, phones and other electronics.

If you have to buy one buy that in advance. Here is a recommended power inverter you can use. This is a 110 V power inverter. If your laptop needs 220 V power get one, which support that voltage.

Other biggest challenge I faced travelling to different countries has different power outlets. Before you travel get a universal power adapter to avoid unnecessary stress. Here is a recommended Universal Power Adaptor.

I will also recommend you to get a better backpack to carry a laptop, phones and other equipment.

Enjoy traveling

travel is fun

As a field test engineer I was traveling an average of 2 to 3 weeks in a month. When you travel this much you must find a way to enjoy each and every trip.

I like photography. During many testing trips, I did photography during late evenings and in weekends.

I traveled with tester who did not want to come out of their hotel room after test session. Some do not want to enjoy the swimming pool in the hotels. They like to watch TV but did not want to go for a walk to see the neighborhood.

If you are one of those who do not like to travel, field and IOT test is not for you. After few initial trips you will feel bored and unproductive.

Even though I stopped travelling 5 years back, I still remember most of trips.

Make all your trips memorable by performing a great test session as well as enjoying your stay.

Here are some of my favorite activities when in a test session.

  • Test from morning to 5 pm.
  • Finish test report and report bugs.
  • Take 15 to 30 minutes rest to get energy.
  • Go with fellow testers to some recommended restaurant. Use Tripadvisor or ask hotel front desk. Also check if some local events are happening during that time.
  • Finish dinner and go for a walk and enjoy the new city.
  • After coming back check emails if something urgent pops up.
  • Put your phone and laptop on charge Go to sleep to recharge for next day.
  • If you are staying for the weekend, make a good plan for Saturday. I like to see the city, do photography or some activity.

Claim expenditures as soon as posssible

expense reporting

I am not good at reporting the expenditures after the test session.

But some of my colleagues in the test team were best on this.

Rule of thumb: Report expenditure on the next working day after returning from trip.

Before loosing any receipts report the expenditure. Many companies have great tools to do this job.

If you lost some receipt from the trip, talk to your manager and there is always a way to fix this.


If we summarize, field test is not just about test. It has many challenges. Try to make the best out of each test session. Find tons of defects in the mobile device and network. Find new ways to test. And believe me you will be the most valuable field test engineer in the entire company.


  1. This is great Info Prashanth. I remember my travels to South Korea doing the same. Very Nostalgic and great piece of information

  2. Thanks Praveen. I never traveled to South Korea. Is it different from other countries for field test?

  3. Neatly written article prashanth ! Loved the positivity ! Keep up the good work .

  4. This is one of the better article written about IOT I ever read. Prashant has a clear vision of the IOT world. Is a pleasure follow this expert in his blog.

  5. Great article. I would like to know more on LTE development and ways to have a career in this hot field of technology.


  6. thank you for sharing

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