What kind of antenna to use with 2 chains routerboard?

[crazyhacker]

please help to novice.
in RB711GA-5HnD specification written that it has 2 chains, it means:

1. that I must connect two identical antennas (like this),
2. or I must connect only dual polarization mimo antenna (like this),
3. or I might connect one antenna (like this) in chain0 and it will be work?

What correct decision, what wrong decision?

[InoX]

all the options work, important is what you need it for

[crazyhacker]

@InoX

all the options work, important is what you need it for

If I correctly understand, in RB711GA-5HnD two chains used for spatial diversity.
so what kind of main benefit or disadvantage will be for these types of antenna’s connections?

[crazyhacker]

maybe somebody can give a link where I can read about routerboard hardware and antenna’s use

[InoX]

you should use google to learn about all tipes of antennas and second chain is not for spatial diversity but it can be used that way.

[crazyhacker]

I rephrase the question, what is purpose of TX in 2 chains in the RB711GA-5HnD, but only with 1 stream?

[normis]

@crazyhacker

I rephrase the question, what is purpose of TX in 2 chains in the RB711GA-5HnD, but only with 1 stream?

To get full speed of 802.11n. Only with two antennas, or dual pol antenna, you can get near 300Mbit wireless speed in 802.11n

[crazyhacker]

@normis

@crazyhacker

I rephrase the question, what is purpose of TX in 2 chains in the RB711GA-5HnD, but only with 1 stream?

To get full speed of 802.11n. Only with two antennas, or dual pol antenna, you can get near 300Mbit wireless speed in 802.11n

I little bit confused, in the brochure for R52n-M (for example) written about 2Nss and speeds up to 300Mbps, and in the brochure for RB711GA-5HnD have written only about MCS7 and not written “Data Rates”.

So, if I correctly understood all routerboard with D in its name (or with two chains) has been working with 2Nss?

[normis]

300Mbit is only possible with 2 chains. R52n-M has two connectors.

[crazyhacker]

@normis

300Mbit is only possible with 2 chains. R52n-M has two connectors.

and why in the specification for routerboard has been written mcs7, but if 2Nss then it must be from mcs8 to mcs15?

[normis]

Where did you see this? From the R52n-M datasheet:


2Nss: 270Mbps @ 800GI, 300Mbps @ 400GI (Max.)
MCS7 20MHz -77 16

[crazyhacker]

@normis

Where did you see this? From the R52n-M datasheet:

2Nss: 270Mbps @ 800GI, 300Mbps @ 400GI (Max.)
MCS7 20MHz -77 16

http://routerboard.com/pdf/330/rb711G-5.pdf
only mcs7, and no one words about 300Mbps

[normis]

What did you expect to see there? MCS data rates are the same for all 802.11n devices
You can go and see the MCS numbers here: http://en.wikipedia.org/wiki/IEEE_802.11n-2009

[crazyhacker]

@normis

What did you expect to see there? MCS data rates are the same for all 802.11n devices
You can go and see the MCS numbers here: http://en.wikipedia.org/wiki/IEEE_802.11n-2009

if RB711GA-5HnD support 300Mbps throughput, I expected to see mcs15

[normis]

Of course it supports MCS15 because it supports 802.11n

You are asking something like “Does this car have wheels”, and I am telling you “If it’s a car, it has wheels, its logical”

[crazyhacker]

@normis

Of course it supports MCS15 because it supports 802.11n

You are asking something like “Does this car have wheels”, and I am telling you “If it’s a car, it has wheels, its logical”

yes, but if I see picture of this car in a store without wheels, I ask myself, do i have to buy wheels separately

anyway, thanks for your answers.

[normis]

All cars have wheels. All RouterBOARDs which have 802.11n support, support all MCS depending on number of chains. One chain - MCS7, two chains - MCS15. Read the 802.11n standard please. This is normal operation, and datasheets shouldn’t include common knowledge that applies to all devices.