Mifi Speed dropped from 25mbps to 1-2mbps

[halfur]

Hi everyone,

I have a Zyxel NR5103E and I am using it with a three-pay monthly unlimited data, text, and call plan. I have good LTE signals (5G is not provided in my area). For the last 1 week, my internet download speed dropped to 1-2mbps. Usually, I was getting around 25mbps download speed (enough for me). Things that I tried to solve this issue:

- Forced the router to connect Band 1 and Band 3

- Changed sim card with a replacement sim card

- Contacted customer service and they told me that the 5G hub works with data sim only. I think this is odd, I do not believe that is an issue. Because I was getting good speeds before having this issue (for the last 3-4 months). If my sim card is not suitable for the device why have I had no issues before? 

I hope somebody can help me. Sometimes I cannot even open a webpage. I need an urgent help.

[crypt0ninja]

Hi @halfur,

Have you checked your post code on the Three Status Checker to see if there's any known/ongoing issues in your area at the moment?

Seems like you have done some good initial testing there.

What Customer Services told you about the 5G Hub working with a data only sim is NOT TRUE lol another case of knowledge gaps and misadvising from Customer Services yet again lol

I use a regular Three Unlimited Data, Text, Calls sim as you do and have no speed issues at all. Mobile Broadband Routers are not restricted to Data Only sims, you can use ANY sim as long as it has an active data plan.

There is clearly an issue somewhere, and for it to change to recently/suddenly it sounds to me like there may be some issue with the connected mast/cell(s).

Could you please share a screenshot of the Cellular Stats page from the NR5103E admin portal? Just want to have a peek at your signal stats (RSRP, RSRQ, SINR etc.) and see what Cell ID you are connected to to check it out on Cell Mapper.

Cheers

[halfur]

Hi @crypt0ninja 

Thanks for your reply and help.

I have checked the Three Status Checker but it says "Our systems haven’t reported any network problems."

I have attached the screenshot of admin portal.

Many Thanks

[crypt0ninja · Accepted solution]

Hi @halfur,

Looking at your signal stats, whist you have good signal strength your Signal/Noise Ratio (SINR) is not good at all at -2 and could explain the poor speed as the antenna is essentially picking up more noise than signal of use.

In my opinion, for a good connection SINRs should be between 5-10, for an excellent connection then 15+. A negative SINR is not good at all.

I would advise to try various locations in your property to determine the location that gives you the best SINR value as there could be something within the routers surroundings that's affecting the noise levels.

I have looked at the mast you are connected to via Cell Mapper and it looks like that mast has B1, B3 and B20 so might be worth trying to add B20 into the mix also to see if that helps with your speeds.

Also, it looks like there is another mast very close to the one you are connected to in the attached pic that only has B1 and B3 so I guess there's a possibility that the router has switched mast as they are close to each other. Only way to specifically lock onto the specific mast you want would be for us to have Cell locking options available in the admin portal but it seems Three have Cell locking options restricted at the moment and only allow us to Band lock with the NR5103E (we've requested for this top be added in a future firmware update if possible).

Hope this helps!

Cheers