This article will explain how to find the best signal possible for your 5G device (NR5101/NR7101/FWA510/FWA710), what to do when you have a bad signal/throughput/speed, how to check your signal strength, what band(s) the device is using and how to troubleshoot this.

Note! This is a follow-up article on NR/5G-Series - Basic Troubleshooting. So if you haven't checked that article out before, please follow that article first.

Table of Content

1) Introduction

1.1 How do I get the best signal possible?

1.2 Put SIM Card into Phone for Comparison

1.3 Finding your Signal Strength

1.3.1 For your Zyxel Device (NR5101/NR7101/FWA510/FWA710)

1.3.2 For Android 

1.3.3 For iPhone

2) Signal Strength & Frequency Bands

2.1 What's a Good Signal?

2.2 What is a Frequency band? 

2.3 What is Carrier Aggregation?

2.4 How do I get the best frequency band(s) possible?

3) Analyzing & Troubleshooting

3.1 Analyzing Signal Strength

3.2 Analyzing Carrier Aggregation (Frequency Bands)

1) Introduction

The most common reason for bad throughput on a 5G device is non-updated device. Please make sure you have the latest firmware and module firmware found here. Otherwise, bad throughput could be the result from a poorly placed device in relation to the cell tower or a poor environment where you don't have much 5G / LTE signal. 

1.1 How do I get the best signal possible?

For NR7101 and FWA710, the antennas built-in are directional antennas and therefore needs to be directed towards the nearest cell tower. This can be done via the Zyxel Air App, where you can find the best signal possible for your outdoor 5G router. 

1.2 Put SIM Card into Phone for Comparison

The first test to do, is to put your SIM card in the device and test the throughput in your mobile phone. Now you have a comparison between the 5G device and your mobile phone which could indicate if you're having good throughput or not.

If you're having the same or lower throughput in your mobile phone as your 5G device, then it means that the fault is in the environment. If you're having higher throughput on your mobile phone than the 5G device, it could be a result of a poorly configuration, or other parameters that could affect the throughput. Please continue the steps below to investigate and solve this issue.

1.3 Finding your Signal Strength

1.3.1 For your Zyxel Device (NR5101/NR7101/FWA510/FWA710)

First login to your device Web GUI (if you don't know how please check the Basic Troubleshooting article). Go to Cellular info and click the yellow arrow ()to find more information:

1.3.2 For Android 

When analyzing your signal strength and frequency bands used. We strongly recommend you use an Android phone because it's more accurate than other devices (such as iPhone). 

You can download this application: 
Network Cell Info Lite & Wifi

1.3.3 For iPhone

Note! The iPhone has sometimes limited information available, and also the SINR information is known to be inaccurate, so it is not optimal. We recommend to borrow an Android phone instead to be compared. 

Again we recommend to use an Android phone because of the availability of information and accuracy compared to iPhone. Please borrow a phone from a friend nearby if you don't have an Android phone.

If you really cannot get an Android phone, please follow these steps below to find more information about your iPhone: 

Call this number below and you'll find more information about your LTE/5G connection:

*3001#12345#*

Then you'll find this screen where you can see more about the Cell info. 

However, if you have only 3 menu options, it could be that the iPhone is still loading. Please refresh this page by closing it and opening it again.

Then you should see more information like this:

If you scroll down to LTE -> Serving Cell Info, you can find more info about the PCI for the LTE signal.

But as you can see, there is not much parameters that you can compare, compared to the Android phone app.

2) Signal Strength & Frequency Bands

Looking at the signal strength and frequency bands, we need to find out what it is and what's a good signal to use and what's a good frequency to use. These two sections about signal strength and frequency bands will help you determine if you have an optimal LTE/5G connection for your device.

2.1 What's a Good Signal?

Please check the table below of what's a good signal and what's a bad signal.

If you are having an Excellent signal, it means that you will probably get max throughput and no interruptions in the connection. A Good signal means that you'll probably get good throughput (but not max), and no interruptions in the connection. A Mid Cell signal means that you'll probably get poorly throughput and no to little interruptions in the connection. While a Cell Edge signal will probably result in low throughput and interruptions in your connection.

You can read more here:

https://support.zyxel.eu/hc/en-us/articles/4406391493778-5G-signal-quality-parameters

2.2 What is a Frequency band? 

All LTE & 5G devices communicate with the cell towers through certain frequencies. For example, why are our mobile phones and radios working at the same time? They are both communicating wirelessly without any clash? It's because they operate on different frequencies. 

Different frequencies have different characteristics where lower frequencies generally have lower speeds but also lower signal loss. Higher frequencies generally have higher speeds, however, also higher signal loss. Therefore, for getting the maximum throughput on your 5G device, you need to be on the higher frequencies. Frequency bands are therefore certain frequency ranges within the 5G and LTE network. 

Please find the list of Frequency bands here:

https://en.wikipedia.org/wiki/LTE_frequency_bands

2.3 What is Carrier Aggregation?

When using a frequency band, there is a limit on how much data can be transferred on that band. Maybe you're connected on a low frequency, or have bad signal strength to the cell tower. Here is where Carrier Aggregation comes in. Carrier Aggregation is combining several frequency bands and are using a combination of bands to increase reliability and, most importantly, higher speeds. The maximum possible data rate per user is increased the more frequency blocks are assigned to a user[1]. So if your phone is having 3 bands aggregated and the 5G device only 1, it is most likely that you will see higher throughput on your mobile phone.

2.4 How do I get the best frequency band(s) possible?

The frequency band is getting automatically assigned to you by your ISP. You will therefore get the preferred band from your ISP. So the 5G device have no power over the selection of frequency bands.

3) Analyzing & Troubleshooting

So ideally, you have now read section two and are aware of what signal strengths are good, what frequency bands and carrier aggregation are, and how to find the LTE/5G information on your phone and on your 5G device. 

In this section, we're going to analyze the two examples pictures below and see what we can do to improve the throughput and/or signal strength here. 

NR7101: 

Android phone:

In our example, we can see that there is some differences for sure: 

3.1 Analyzing Signal Strength

Looking at the RSRP (average power of the received reference signals), we can see that the Android phone is struggling a lot with getting a proper signal, while the NR7101 is having excellent signal. For RSRQ (characterizes the quality of the received reference signals), the Android phone is having a decent signal while the NR7101 is receiving a good quality signal. Lastly, the SINR (Signal Interference + Noise Ratio) is not available on the Android phone from what we can see and NR7101 shows that there is some interference and noise on the frequency band, but not too much. 

3.2 Analyzing Carrier Aggregation (Frequency Bands)

For the frequency bands, we can see that the phone & NR7101 has completely different bands used and this is not very common if you're using both devices in the same environment. This could be because the phone and NR7101 is connecting to two different cell towers. What we can do is to use the Zyxel Air App to direct the NR7101 towards the same tower (if the mobile phone shows stronger signal). However, let's still analyze both device's frequency bands below:  

Android Main Band - Band 66 = 1710 – 1780 MHz UL / 2110 – 2200 MHz DL

NR7101 Main Band - LTE_BC28 = 703 – 748 MHz UL /758 – 803 MHz DL

Here we can see that the Android is using a higher frequency as their main band (66), while the NR7101 is using a quite low frequency (28). This will probably result in lower speeds for the NR7101. But because the signal quality was low on the Android phone, we could see higher throughput on the mobile phone, but a lot more unstable connection (drop-outs will be common). This is also a preference on the device. Our products are designed to get the most stable signal for professional settings and not the maximum throughput based on speed tests. 

Taking a look at the list of frequecies, NR7101 is also using band 1 (LTE_BC1) and band 3 (LTE_BC3) which operates on 2100 MHz as well as 1800 MHz. This is good bands to be utilized the most. Because both band 1 and 3 are much more suitable than band 28 to be the serving (main) band, I would think about contacting my internet provider to see why band 28 is preferred over 1 & 3. They have the same signal strength, but I would get so much more out of band 1 for example. 

Another thing we can do is to lock band 1 (or the Cell ID of band 1), however, the carrier aggregation could be affected by locking a certain main band, which would slow down our speeds. So therefore, please check with your ISP on what Serving (main) bands support what carrier aggregations (CAs) to get the optimal band combinations, connection stability and throughput. 

Read here how to lock your Cell ID: NR/FWA Series [5G] - Cellular Lock

4) What Throughput to Expect?

Disclaimer! Cellular network is dependent on the ISP coverage and load. We have little to no influence throughput capacity in your area. We can only configure the device most optimal to your device.

Therefore, under normal circumstances, the average speed is around 500-700 mbit/s where the maximum speeds are around 1 to 1,5 gbit/s. But this is dependent on your signal strength, noise ratio and CAs used and ISP preferences/cell tower configurations.