Can Network Congestion Decrease Wireless Internet Speeds?

When 4G LTE is at its best, it has download and upload speeds fast enough to rival some cable internet connections in rural areas. People in rural areas consistently report 4G LTE download speeds of more than 20 Mbps in fringe areas and more than 10 Mbps in remote areas. Average upload speeds, too, top 5 Mbps in fringe areas and 3 Mbps in remote areas on some networks.

Unfortunately, network congestion can have a negative effect on your wireless internet speeds. If your fixed wireless internet speeds are lower than what you’d typically see in a fringe or remote rural area, too many people could be using your tower at once.

Why do rural cell towers have limited bandwidth?

Every 4G LTE tower has a specific amount of space or “bandwidth block” of radio spectrum on the network: 1.4 MHz, 3 MHz, 5 MHz, 10 MHz, 15 MHz, or 20 MHz. While the 20 MHz block provides the highest capacity, carriers often allocate smaller blocks for rural towers because radio spectrum is limited and there are usually fewer people using cell towers in rural areas.

How is bandwidth related to internet speeds?

A tower’s bandwidth is the maximum amount of online data it can process at one time. When there isn’t a huge amount of data moving through the tower, it can process everything right away and at full speed. When the number of data requests exceeds the tower’s bandwidth, the tower can’t process everything at once. The tower throttles internet speeds so that, at least, it doesn’t have to deny any requests – it can just take them more slowly instead.

How many people can use your tower at once?

A tower can only support about 200 connected devices at full speed per 5 GHz of bandwidth. If there are more devices connected to your tower, your 4G LTE speeds will suffer. Here’s how many devices – such as wireless routers, phones, or tablets – your tower can support at full speed at one time, based on its bandwidth block:

Bandwidth block Number of devices
1.4 MHz 60
3 MHz 120
5 MHz 200
10 MHz 400
15 MHz 600
20 MHz 800

How much does congestion decrease download and upload speeds?

Because 4G LTE designates blocks of radio spectrum specifically for downloads and specifically for uploads, congestion will probably affect your internet speeds unevenly. If either your download or upload speed drops independently of the other, it could be a sign that network congestion on the downlink or uplink frequency is affecting your internet speeds.

Towers typically distribute their bandwidth evenly between connected devices, which means your internet speeds will decrease in proportion to the number of extra devices on the network. If 800 devices connect to a 10 MHz tower with a 400-device limit, for example, a 20 Mbps download speed could become 10 Mbps and a 5 Mbps upload speed could become 2.5 Mbps.

Stephen Kota

About Stephen Kota

Founder & Primary Author

Stephen enjoys photography, boating and gardening. He cares for pet Kois in his water garden.

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