Why do I have good signal strength, but slow internet speeds?
When fixed wireless internet is at its best, it has internet speeds fast enough to rival some rural cable internet connections. People consistently report 4G LTE download speeds of more than 20 Mbps in fringe rural areas and more than 10 Mbps in remote rural areas. Average upload speeds, too, top 5 Mbps in fringe areas and 3 Mbps in remote areas on some networks.
Sometimes though, fixed wireless internet speeds fall short, even when you get great cellular coverage. These slow speeds could be due to too many devices on your local network or poor Wi-Fi (to find out, use an ethernet cable to connect your device directly to your wireless router) – or it could be due to network factors outside your control.
Let’s take a closer look at why strong wireless connections aren’t always fast.
Signal Strength vs. Internet Speeds
Signal strength measures cellular coverage in a particular area. You can view your signal strength as bars on your phone or as numerical values by:
- Navigating to “Settings” > “About Phone” > “Network” or “Status” on Android
- Dialing *3001#12345#* on iOS
Carriers measure the signal strength of their cell towers in decibels relative to one milliwatt (dBm), which has no direct correlation to megabits per second (Mbps) of internet speed. There’s no formula to convert signal strength into internet speeds because different towers have different potential speeds based on a range of other factors.
Why Your Strong Connection is Slow?
Cell towers transfer online data between clients and servers using radio waves. The build of the tower you’re connected to, as well as its frequency bands and bandwidth blocks, all have a significant effect on internet speed independent of signal strength.
How Frequency Affects Wireless Internet Speed
Towers that use lower frequency bands to transfer data are slower but have better signal ranges. Towers with higher frequencies are faster but have worse cellular coverage.
Most 4G LTE towers have frequency bands of 600 MHz, 800 MHz, 900 MHz, or 1900 MHz. Because higher frequencies have higher potential download and upload speeds, a 4G LTE tower that uses the higher frequency 1900 MHz band has faster speeds than a tower that uses the lower frequency 600 MHz band, even when the signal strength of both towers is the same.
5G towers usually have frequency bands of 3100 to 3550 MHz, 3700 to 4200 MHz, 27.5 to 28.35 GHz, or 37 to 40 GHz. These higher frequencies have higher potential download and upload speeds, which means you can get faster speeds with poorer signal strength.
How Bandwidth Affects Internet Speed
Every 4G LTE tower uses a specific bandwidth block of radio spectrum – 1.4 MHz, 3 MHz, 5 MHz, 10 MHz, 15 MHz, or 20 MHz – within its frequency band. Each of these blocks supports a limited number of devices at full speed – about 200 per 5 GHz of bandwidth.
If too many devices connect to a tower at one time, it splits limited bandwidth between all these devices. If your tower has less available bandwidth because, for example, it only has 1.4 MHz of available bandwidth, your signal might be strong, but your internet speeds could be slow.
Because wireless internet has separate bandwidth blocks for downloads and uploads, congestion often affects internet speeds unevenly. If just your download or just your upload speed is slow, it could be a sign that congestion is what’s slowing down your internet speeds.
Towers almost always distribute 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.
When fixed wireless internet works out for its users, it’s an excellent internet solution for people in rural areas without access to cable internet.