Dual band refers to a device which uses two different frequencies to communicate.

Dual radio refers to a device which uses two different protocols to communicate.

Maybe an illustration would help. A dual band device is like a person at a party who can move between two different rooms (different frequencies) to talk with other people, while a single band device would be limited to talking to people in only one room. On the other hand, a dual radio device can speak with people who speak in two different languages, while a single radio device can only speak one language.

A dual radio device is typically used as an intermediary between two different networks like 802.11 (like WiFi) and 802.15.4 (like many wireless sensors).

Dual band refers to a device which uses two different frequencies to communicate.

Dual radio refers to a device which uses two different protocols to communicate.

Maybe an illustration would help. A dual band device is like a person at a party who can move between two different rooms (different frequencies) to talk with other people, while a single band device would be limited to talking to people in only one room. On the other hand, a dual radio device can speak with people who speak in two different languages, while a single radio device can only speak one language.

A dual radio device is typically used as an intermediary between two different networks like 802.11 (like WiFi) and 802.15.4 (like many wireless sensors).

Bradley Nelson confusion solved.

Thank you.

Dear Muhammad Asghar Khan,

Its indeed a very interesting question.

The system you are talking about is a dual band (as it can simultaneously transmit wireless signals in two bands 2.4 GHz and 5 GHz).

A dual band radio can be of two types:

1: One which employs same transmission technologies at both the 2.4 GHz and 5 GHz bands. For example: Dual band WiFi routers which uses 802.11g at both the bands. These dual band routers have several advantages over single band routers (2.4 GHz or 5 GHz) like they can easily support HD streaming, live gaming, large file transfer, large coverage area and strong signal strength etc. Dual band radios are mainly used for dense area networks to support a large number of users. Similarly, we have dual band WiFi adapters which performs the same task of receiving simultaneously at two different bands. A dual band requires the antenna to be capable of operating at these two frequencies.

2: Another type of dual band radio is the one which employs two separate transmission technologies like 802.11(WLAN) at one band and 802.15.4 (WPAN) at other (example according to your question). The main motivation to pursue dual radio is to segregate data types onto different RF bands. For example 5 GHz can be used to support highly sensitive voice and video and 2.4 GHz can be utilized for normal data traffic from access points. Since they are using different RF bands the two data types are segregated and has no interference. This is just like creating two RF networks.

Now coming to your question: 802.11 is deployed for air-air link (at 5 GHz), another 802.11 is deployed for air-ground (at 2.4 GHz), and 802.15.4 is deployed for air-air (at 2.4 GHz).

Since the systems is operating simultaneously at 2.4 GHz (802.11[air-ground] and 802.15.4[air-air]) and 5 GHz (802.11[air-air]) bands, it is surely a dual band system (two operating bands).

The concept of dual radio in the application system discussed by you is like utilizing the same band for two different applications by the use of two different technologies (This is also dual radio). and they will not interfere with each other as one is air-air and one is air-ground.

Let me refine the definition: I have two bands 2.4 GHz and 5 GHz and I can use both the bands to support different number of applications by using different technologies. But off course, this will increase the complexity of your systems and its access points. If you are using two different technologies (802.11 and 802.15.4) at 2.4 GHz you can simultaneously support a WLAN (air-air) and WPAN (air-ground). This is dual radio. You can also use dual radio at 5 GHz but again in order to have no interference these signals should be separated thats why at 2.4 GHz one application is air-air and one is air-ground.

The system is Dual Band Dual Radio.

Feel free to ask anymore questions if you still have doubts.

Thanks and Regards,

Vinay Trivedi

IIT Patna

INDIA

Thank you Bradley Nelson for the example.

I think I have taken much time to write the response.

Regards,

Vinay Trivedi

IIT Patna

INDIA

Vinay K. Trivedi You have solved my problem.Moreover, you have very fine understanding about the topic i guess.Thank you so much for your valuable comments.

Dear colleagues

welcome,

Indeed i can answer the question based on the example brought by Muhammad.

The answer of Bradley is taken from the example in the question. While the answer of Vinay tries to give a physical ad logical justification to the expressions dual band and dual radio.

From my point of view radio for a communication engineer means the transmission of signals using radio waves which are electromagnetic waves lying in certain range of the electromagnetic spectrum. Radio may point out to radio equipment transmitter, receiver or transceiver.

So, your radio may be two band radio as it operates in two bands. It is irrelevant which protocol is used on each band. If you want to classify the protocol at the same time then you can say two bands with two different standards.Here dual you mean dual standard radio systems. Which dictates also using two different transmission bands.

So, i think one has to be more specific in defining his terms to remove the ambiguity.

Best wishes

Interesting elaboration, by Dr Zekry. My answer was more in line with Bradley's, and I'll use a historical example to demonstrate why.

In analog days, there is/was something called "multiband SW receiver." This was a receiver in which one could dial in any number of frequency bands, but the received signals were always 5 kHz wide analog AM. (Some of these could also demodulate single sideband, on any channel.)

On the other hand, there are/were also AM/FM radios, in which the MW AM and the VHF FM each consisted of only one band. I've never heard anyone refer to AM/FM radios as "dual band." Internally, AM/FM radios are indeed two separate radios. Where instead, multiband radios consist only of a way to change where the tuner resonates. All the rest of the process is identical.

Dear All,

Muhammad Asghar Khan , Prof. Abdelhalim Zekry , Prof. Albert Manfredi

Thanks for all the responses.

Please find similar discussions made at CISCO forum previously about Dual Radio and Dual Band. They are very clear about the dual concept of both Radio and Bands. We have existing dual band dual radio products of access points from different firms also like CISCO.

Please see the links for more details.

1: https://community.cisco.com/t5/wireless-and-mobility/access-point-dual-band-dual-radio/td-p/2176047

2: https://community.cisco.com/t5/wireless-and-mobility/dual-band-concept/td-p/3097503

Thanks and Regards,

Vinay Kumar Trivedi

IIT Patna

INDIA

Dear all

Please find the some other discussions links on dual-band and dual-radios and single/dual/tri-band Wi-Fi routers except the link given by the Vinay Kumar.

1. https://community.arubanetworks.com/t5/Wireless-Access/Dual-Radio-amp-Dual-Band/td-p/66088

2. https://www.linksys.com/us/r/resource-center/basics/multiple-wifi-bands-difference/

Hope you can find the answer.

Ashok Kumar

GWEC Ajmer India