Self-isolation and subsequent remote work have sparked interest in mobile internet, and I've been receiving more questions in the comments or via private messages about setting up reliable network access from rural areas. During the pandemic, I noticed that the load on the network increased not just exponentially, but astonishingly: a previously uncongested Beeline tower was delivering up to 40 Mbps for downloads, but by the end of April, the speed dropped to 1 Mbps. It was around May that I came up with the idea to conduct a comparative test of routers from different categories that support channel aggregation, which can improve network speed even when the tower is crowded. The theory and tests are below.
A Bit of Theory
What affects the data transfer speed from the base station (BS) to the subscriber? Removing interference, the distance between the subscriber and BS, the load on the BS, and the channel congestion from the BS to the internet access point leaves only the channel width, modulation, transmission frequency, and the number of these channels.
Let's start with the frequency: LTE in Russia operates on frequencies of 450, 800, 900, 1800, 1900, 2100, 2300, 2500, and 2600 MHz. If we recall physics, it was clearly explained that lower frequencies have better penetration ability and attenuate over greater distances. Therefore, in urban areas, higher frequencies with more closely spaced BSs are typically used, whereas in rural areas, lower frequencies are more commonly utilized, allowing for fewer towers. It also depends on the frequency allocated to the operator in the current region.
Channel width: In Russia, channel widths of 5, 10, and 20 MHz are most commonly encountered, although the width can range from 1.4 to 20 MHz.
Modulation: QPSK, 16QAM, 64 QAM, and 256 QAM. This depends on the communication operator. I won't delve into the technical details, but the rule here is: the higher the modulation in this ranking, the higher the speed.
Number of Channels: The receiving radio module can operate in channel aggregation mode if supported by the service provider. For example, a tower transmits data at frequencies of 1800 and 2600 MHz. An LTE Cat.4 module can only operate at one of these frequencies. A Category 6 module can work with both frequencies simultaneously, combining speeds from both modules. A Category 12 device will operate with three carriers: for example, with two at a frequency of 1800 MHz (1800+1800) and one at a frequency of 2600 MHz. The actual speed will not be three times as high, but will depend only on the load of the base station and the internet channel width of the base station itself. I have encountered cases while working with Cat.6 where using one channel provided speeds of 40 Mbps, while using two channels offered 65-70 Mbps. Quite a good increase, wouldn't you agree?
Test Idea
This is how I came up with the idea to test routers of different categories to determine the real picture that an average user will see. The challenge is to take routers from the same series or only ones with different radio modules, as routers from different manufacturers will likely have different components that can affect the measurement results. Therefore, I decided to test one manufacturer, but different routers.
The second step was to choose the types of devices for the tests: one could simply take a router and connect an antenna via a cable assembly, but practice shows that the user wants to get an all-in-one device that simply requires inserting a SIM card and connecting the device to the network. Thus, I decided to test integrated units, that is, routers and antennas in one enclosure.
The third step was to choose the manufacturer: Zyxel has the largest range of integrated units with different LTE categories, so the choice was simply obvious.
For the test, I took the following routers: LTE 7240, LTE 7460, and LTE 7480.
Testing methodology
To evaluate the capabilities of the routers, it was decided to conduct both a 'synthetic' test and a real one. The synthetic test involved measuring speed at a distance of about 200 meters from the base station, aligned with the radiating antenna, allowing for optimal signal strength. The connection was made to the MegaFon towers, as they provided the maximum channel width of 20 MHz for this location. I tested the routers in two regions, where the operator's coverage map promises speeds of up to 150 and 300 Mbps, respectively. The real test involved placing the router at my home, where I previously tested other routers. The connection conditions in this mode are much more challenging, as the distance to the tower is 8 km, there is no line of sight, and the signal encounters trees along the way. In total, there were three tests:
- Distance to the tower ~200 m. Area with a maximum claimed speed of 150 Mbps. Testing time 12-1 PM.
- Distance to the tower ~200 m. Area with a maximum claimed speed of 300 Mbps. Testing time 12-1 PM.
- Distance to the tower ~8000 m. No line of sight. Area with a maximum claimed speed of 150 Mbps. Testing time 12-1 PM.
All tests were conducted with the same SIM card on weekdays. The time was chosen around 12-1 PM to avoid morning and evening peak loads on the base stations. Tests were performed several times on two different server using the Speedtest service: Moscow Megafon and Moscow RETN. The speeds varied slightly, as servers they had different loads. It’s time to start the tests, but first, let's look at the external description and technical specifications for each router.
Zyxel LTE 7240-M403
The entry-level router from the all-weather LTE devices line by Zyxel. It can be mounted on a wall using a special plate or secured to a pole with clamps. It does not have a mounting system with multiple degrees of freedom, so it's advisable to prepare a pole for external installation to direct it more accurately towards the base station. Despite its small size, it has a good antenna and is easy to install: the SIM card and Ethernet cable can be inserted into the casing, all sealed by a special cover. The router is equipped with a Wi-Fi module, allowing not only wired internet access but also providing decent wireless coverage in the surrounding area. It has a module supporting Cat.4, achieving a maximum download speed of 105 Mbps during tests—a great result for such a device. However, in real-world testing, with a distance of over 8 km to the base station, the maximum speed reached was 23.5 Mbps. Some may say this isn't much, but many fiber optic operators demand from 500 to 1200 rubles per month for a 10 Mbps connection, plus installation costs ranging from 10,000 to 40,000 rubles. Thus, mobile internet turns out to be cheaper and much simpler to install and connect anywhere. Overall, this router will allow for comfortable remote work, as well as enjoying video streaming and fairly quick web browsing. If you already have infrastructure in place with IP cameras or a video surveillance system, just adding this router will enable you to monitor your security system remotely.
Zyxel LTE7460-M608
This device is a logical development of the legendary Zyxel LTE 6100, which ushered in the era of LTE all-in-one routers. However, the previous model had an internal block that was located indoors, while the antenna with the modem was outside. The device complies with LTE Cat.6 technology, which implies the aggregation of two carriers and an increase in incoming speed if supported by the base station. Installing a SIM card in the router is a non-trivial task since the board with the injector is deep inside the antenna, and when mounting at height, there is a good chance of dropping the SIM card. Therefore, I highly recommend inserting the card at the bottom and then mounting the router at height. As this is the first all-in-one device to appear in the Zyxel lineup, it is not equipped with a Wi-Fi module, so Internet access can only be obtained via cable. This also allows choosing a Wi-Fi point that can be installed in the house. Additionally, the Zyxel LTE7460 easily integrates into the existing infrastructure and can operate in bridge mode. In terms of speed characteristics, the router managed to demonstrate a solid 137 Mbps download speed in tests — not every wired provider achieves such speed over cable. The maximum upload speed in the same test was over 39 Mbps, approaching the theoretical limit of upload from the client to the network. In real-world trials at long distances, the router also performed confidently, allowing downloads at speeds up to 31 Mbps and uploading data at speeds exceeding 7 Mbps. For those living in rural areas without access to wired networks, such speeds are quite sufficient for the needs of a whole family — education, entertainment, and work.
Zyxel LTE7480-M804
Finally, it’s time to discuss the top model in the all-in-one router lineup in this test. The Zyxel LTE7480 supports LTE Cat.12 technology and can operate with three carriers simultaneously. The possible combinations of aggregation modes are detailed in the technical specifications table, but I’ll simply say — it really works! The maximum speed achieved during testing was over 172 Mbps! To put it in perspective — that’s about 21 MB/s. In other words, a 3 GB movie would download in just 142 seconds! During that time, even a kettle wouldn’t boil, and a high-quality film would already be on your computer's hard drive. It's important to understand that speed will depend on the load of the base station and the channel bandwidth connected to it. I believe that at night, when there are fewer users taxing the network, I could have achieved even greater speeds on the tested tower. Now, moving from admiration to description and drawbacks. The manufacturer listened to users and made mounting more comfortable, as well as sim card integration: now it is located not deep within the case, but on the end — under a protective cover. The mounting bracket allows the router to be installed on a wall of your home or on a pole and precisely adjust the antenna towards the base station — the angle of rotation can be adjusted both horizontally and vertically up to 180 degrees. The device is also equipped with a Wi-Fi module and, in addition to wired data transmission, can provide mobile devices with internet access via a wireless channel. During the test, it was noticeable that the upload speed was lower than that of other models, which I suspect is related to two factors: either the firmware is still not completely refined, or the four antennas are positioned closely in the compact case: the dimensions of the Zyxel LTE7480 are the same as those of the Zyxel LTE7460, while having twice as many antennas. I contacted the manufacturer, and they confirmed my suspicions — it’s challenging to find such communication conditions as I experienced, with the distance from the base station being 8 km.
Summary
In summary, we should refer to the speed measurement table. It shows that even when located in the same spot, different speeds can be obtained because servers may be under varying loads. Additionally, the load on the base station also plays a role. The speed tests demonstrate that over a long distance of about 8.5 km, channel aggregation is unlikely to work (or perhaps my base station simply does not support aggregation), and the emphasis shifts to amplifying the built-in antennas. If you are situated near the base station or within line of sight, it makes sense to acquire devices supporting Cat.6 or Cat.12 technology. If you have the budget to purchase the Zyxel LTE7460 router, it might be worth slightly increasing your budget to get the Zyxel LTE7480 router, which supports Cat.12 and has a built-in Wi-Fi module. However, if you're far from the base station but have all the infrastructure set up in your home and only need an internet access point, you can consider a mid-range device from the lineup. For those who are not demanding about internet speed and want to save money, the Zyxel LTE 7240 is a great option — this starter model is compact, easy to install, and can provide a comfortable level of web surfing.
Source: habr.com
