Self-isolation and subsequent remote work stirred up interest in the mobile Internet, and in the comments or in private messages, they increasingly began to ask me questions about arranging normal access to the network from the private sector. During the pandemic, I noticed that the load on the network increased not just by a multiple, but incredibly: the previously free Beeline tower gave out up to 40 Mbps for downloading, and at the end of April the speed dropped to 1 Mbps. And somewhere in May, the idea was born to conduct a comparative test of routers of different categories that support link aggregation, which means they will increase the network speed even when the tower is loaded. Theory and tests under the cut.
Some theory
What determines the data transfer rate from the base station (BS) to the subscriber? If we remove interference, the distance between the subscriber and the BS, the load on the BS and the channel load from the BS itself to the Internet access point, then only the channel width, modulation, data transmission frequency and the number of these channels remain.
Let's start with the frequency: LTE in Russia operates at frequencies of 450, 800, 900, 1800, 1900, 2100, 2300, 2500 and 2600 MHz. If you recall the physics, then it was clearly explained that lower frequencies have better penetrating power and attenuate over a greater distance. Therefore, in the city, high frequencies are usually used with a denser location of the BS, and outside the city, low frequencies are more often used, which makes it possible to install towers less often. It also depends on what frequency was allocated to the operator in the current region.
Channel width: In Russia, the most common channel width is 5, 10 and 20 MHz, although the width can be from 1.4 to 20 MHz.
Modulation: QPSK, 16QAM, 64QAM and 256QAM. It already depends on the carrier. I will not delve into the technical features, but the rule applies here: the higher the modulation in this rank, the higher the speed.
Number of channels: The receiving radio can operate in link aggregation mode if supported by the carrier. For example, the tower transmits data at a frequency of 1800 and 2600 MHz. An LTE Cat.4 radio will only be able to operate on one of these frequencies. Category 6 module will be able to work with both frequencies at once, summing the speed from two modules at once. A category 12 device will work with three carriers at once: for example, two at a frequency of 1800 MHz (1800 + 1800) and one at a frequency of 2600 MHz. The actual speed will not be x3, but will depend only on the workload of the BS and the width of the Internet channel of the base station itself. I have seen cases when working with Cat.6, when working with one channel gave a speed of 40 Mbps, and with two channels 65-70 Mbps. Agree, a good addition!
test idea
This is how I got the idea to test routers of different categories to find out the real picture that will open to the average user. The problem is to take routers of the same series or only with different radio modules, since routers from different manufacturers will most likely use different stuffing, which can affect the measurement results. Therefore, I came up with the idea to test only one manufacturer, but different routers.
The second step was to select the type of devices for testing: you can simply take a router and connect an antenna to it through cable assembly, but practice has shown that the user wants to get a combine into which it is enough to insert a SIM card and turn on the device to the network. So I came up with the idea to test monoblocks, that is, a router and an antenna in one case.
The third step I decided on the manufacturer: Zyxel has the largest line of monoblocks 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 technique
In order to evaluate the capabilities of routers, it was decided to conduct a slightly "synthetic" test and a real test. The synthetic test consisted in the fact that the speed measurements were carried out at a distance of about 200 meters from the base station in the range of the radiating antenna, which made it possible to obtain the best signal level. The connection was made to the Megafon towers, as they provided the maximum channel width for this place of 20 MHz. Well, I tested routers in two regions, where, according to the coverage map, the operator promises speeds of up to 150 and up to 300 Mbps, respectively. The real test was to place the router in my house, where I tested the old routers. Communication conditions in this mode are much more difficult, since the distance to the tower is 8 km and there is no line of sight, and there are trees in the signal path. So, there were three tests in total:
- The distance to the tower is ~200 m. The zone with the maximum declared speed is 150 Mbps. Testing time 12-13 hours.
- The distance to the tower is ~200 m. The zone with the maximum declared speed is 300 Mbps. Testing time 12-13 hours.
- Distance to tower ~8000 m. No line of sight. Zone with a maximum declared speed of 150 Mbps. Testing time 12-13 hours.
All tests were carried out with the same SIM card on weekdays. The time was chosen around 12-13 hours to avoid morning and evening peak loads on the BS. The tests were carried out several times on two different servers using the Speedtest service: Moscow Megafon and Moscow RETN. The speed was somewhat different, as the servers have different load. It's time to start testing, but first, an external description and technical specifications for each router.
Zyxel LTE 7240-M403
Starter router from Zyxel's line of all-weather LTE devices. It can be mounted on the wall of the house using a special plate, or it can be fixed to the pipe using clamps. It does not have a mount with several degrees of freedom, so it is worth preparing a rod for external mounting and a more accurate direction to the BS. Despite its small size, it has a good antenna and ease of installation: a SIM card and an Ethernet wire are inserted into the case, and a special cover seals it all. The router is endowed with a Wi-Fi module, which makes it possible not only to use wired Internet access, but also to decently cover the surrounding area with a wireless signal. The router has a built-in module with support for Cat.4 and the maximum download speed achieved during the tests was 105 Mbps - an excellent result for such a device. But when testing in real conditions, when it was more than 8 km to the base station, it was possible to achieve a maximum speed of 23,5 Mbps. Someone will say that this is not much, but often there are fiber optic line operators who want from 10 to 500 rubles a monthly fee for 1200 Mbps, and the connection will also cost 10-40 thousand rubles. Thus, the mobile Internet is both cheaper and much easier to install and connect at any point. In general, this router will allow you to comfortably work remotely, as well as enjoy watching videos and quite fast surfing the net. If you already have a ready-made infrastructure with IP cameras or a video surveillance system, then it is enough to add such a router to remotely monitor your security system.
Zyxel LTE7460-M608
This device is a logical development of the legendary Zyxel LTE 6100 device, which opened the era of LTE monoblock routers. True, the previous model had an indoor unit, which was located indoors, and the antenna with the modem was outdoors. The device complies with LTE Cat.6 technology, which implies aggregation of two carriers and an increase in the incoming speed, if supported by the base station. Installing a SIM card in a router is a non-trivial action, because the board with the injector is located deep inside the antenna, and when mounted at a height, there is every chance of dropping the SIM card. Therefore, I highly recommend installing the card at the bottom, and then mounting the router at a height. Since this is the first all-in-one device that appeared in the Zyxel line, it is not equipped with a Wi-Fi module, so Internet access can only be obtained via cable. In this case, there is the freedom to choose a Wi-Fi point that will be installed in the house. Also Zyxel LTE7460 is easily integrated into existing infrastructure and can work in bridge mode. As for the speed characteristics, the router in the tests was able to demonstrate a solid 137 Mbps for downloading - not every wired provider gives such a speed over the cable. The maximum upload speed in the same test was more than 39 Mbps, which is close to the theoretical threshold for uploading from the client to the network. As for the real test over a long distance, the router also felt confident and allowed to download at speeds up to 31 Mbps, and give data at speeds of more than 7 Mbps. In the case of living outside the city and the lack of the ability to connect to wired networks, this speed is quite enough for the needs of the whole family - education, entertainment and work.
Zyxel LTE7480-M804
Finally, the turn came to the top model in the line of monoblock routers in this test. Zyxel LTE7480 supports LTE Cat.12 technology and is able to work with three carriers at once. Possible combinations of aggregation modes are presented in the table with TTX, and I will simply say - it really works! The maximum speed achieved during testing was over 172 Mbps! To understand the order of numbers, this is about 21 MB / s. That is, a 3 GB movie at this speed will be downloaded in 142 seconds! During this time, even the kettle will not boil, and the film in good quality will already be on the computer disk. Here you need to understand that the speed will depend on the workload of the base station and the channel bandwidth that is connected to this BS. I think that at night, when subscribers load the network less, I could get even more speed on the test tower. Now I will move from admiration to description and cons. The manufacturer listened to the users and made the installation more comfortable, as well as the integration of the SIM card: now it is not in the depth of the case, but at the end - under a protective cover. The mounting bracket allows you to install the router both on the wall of the house and on the extension rod and accurately align the antenna to the BS - the angle of rotation horizontally and vertically is 180 degrees. The device is also equipped with a Wi-Fi module and, in addition to transmitting data via wire, can provide mobile devices with Internet via a wireless channel. During the test, it was noticeable that the outgoing speed was lower than that of other models, and I assume that this is due to two points: raw firmware or a dense arrangement of 4 antennas in a compact case: the dimensions of the Zyxel LTE7480 are the same as those of the Zyxel LTE7460, and twice as many antennas. I contacted the manufacturer, and they confirmed my assumptions - nevertheless, it is not easy to find such communication conditions as I had, with a distance of 8 km from the BS.
Results
Summing up, it is necessary to refer to the speed measurement table. It follows from this that even being at the same point, you can get different speeds, since the servers can be loaded to a greater or lesser extent. In addition, the load on the base station also affects. Speed ββmeasurements also show that over a long distance, about 8.5 km, channel aggregation is unlikely to work (or it's my BS simply does not support aggregation) and the gain of the built-in antennas comes to the fore. If you are from the base station in close proximity or within line of sight, then it makes sense to purchase devices that support Cat.6 or Cat.12 technology. If you have the money to buy a Zyxel LTE7460 router, then it makes sense to slightly increase the budget to take a Zyxel LTE7480 router with Cat.12 support and a built-in Wi-Fi module. If the BS is far away, but you have the entire infrastructure in the house and only the Internet access point is missing, then you can take the average device from the line. Those who are undemanding about the speed of accessing the network and want to save money should look towards the Zyxel LTE 7240 - this starter model is compact, easy to install and is able to provide a comfortable level of surfing the net.
Source: habr.com