Why does Wi-Fi have so much more bandwidth than Bluetooth? [closed]

Question

While researching wireless communication protocols for a potential application, I came across this page on Wikipedia which lists throughput rates for both Bluetooth and 802.11 networks: http://en.wikipedia.org/wiki/List_of_device_bit_rates

Here is a relevant selection from the link:

• 1 Mbps - Bluetooth 1.1
• 3 Mbps - Bluetooth 2.0+EDR
• 24 Mbps - Bluetooth 3.0, Bluetooth 4.0
• 54 Mbps - 802.11a
• 600 Mbps - 802.11n

Why does Bluetooth have so little throughput compared to the Wi-Fi standards?

Is it simply because the standard set by the governing body intentionally sets a lower data transfer rate in order to allow hardware costs to stay low?

Is it possible we could get a "Bluetooth 5" with bandwidth on the order of 802.11a or 802.11n, or is there some deliberate design decision that results in low transfer rates (e.g. sacrificing speed in favor of low power consumption)?

Edit: to be clear, I understand that the listed data rates are theoretical maximums and do not reflect real world performance.

Answer 1

Both Bluetooth and WLAN [802.11] operates on ISM band 2.4GHz. additionally WiFi has a version that operates on 5 Ghz band too.

1] Why WiFi has more bandwidth or speed than Bluetooth?

Because WiFi is designed to have more speed than Bluetooth. The factor which makes the difference is power usage. Bluetooth is designed as a technology that uses very low amount of power. So data rates are restricted in the PHY [physical layer used by Bluetooth] to achieve this low power usage. Basically Bluetooth's PHY layer uses low data rate's because low data rate require very little power.

WiFi is designed as a wireless rival of Ethernet. So bandwidth [speed] matters. So WiFi's physical layer [PHY] is designed to have higher data rates. Higher data rates means more power, this also means your devices battery power will be drained faster.

2] Is it possible to have Bluetooth-5 with more bandwidth than 802.11-n?

Absolutely possible, if Bluetooth protocol stack is placed on top of a higher bandwidth PHY, Bluetooth will achieve higher bandwidth.

There is a technology called AMP [Alternate MAC PHY] as part of Bluetooth spec 4.0 [if my memory is correct], where Bluetooth protocol stack sits on top of WLAN [802.11] MAC. This approach was to solve Bluetooth's bandwidth problem. AMP is not used by many people today I guess.

3] PHY Data rates and achievable data rates

The rates advertised [54 mbps - 802.11 a] is the maximum raw throughput achievable at PHY level , in "ideal channel conditions". Which means in labs. typically when we use it in real world, there will be interference and so retries. This will reduce the bandwidth. also the protocol stack layer and applications on top of PHY will add latency on top of it. typically with a best performing implementation of 802.11a , the maximum achievable application level throughput in real world scenarios is around 40 MBPS.

Hope it helps. I am happy to answer more, if you got more questions on this.

Answer 2

There are many differences between Bluetooth and WiFi protocols, most of them affect the throughput. However, the most important factor is the channel bandwidth. Bluetooth operates at 1MHz channels, while WiFi uses 20MHz and 40MHz channels, effectively providing much better throughput. Both BT and WiFi have power saving schemes (and many other properties) which affect the throughput but these are secondary to channel width.