Best Long Range Wireless Cards for Linux
We compare four of the most popular long-range wireless cards for use with linux. These cards are popular with linux users because of their power (range), their good sensitivity, and for the fact that they all use well supported chipsets with very good linux driver support. These cards can be used for everyday wireless networking, but importantly, are capable of performing wireless packet injection and monitor mode, and as such are well suited for penetration testing with the likes of Kali Linux and its venerable predecessor BackTrack Linux. Here we look specifically at their sensitivity capabilities.
The chart above plots the sensitivity test results from the four cards and the data obtained using the same 9dBi omni for each.
The results show a striking view of the sensitivity differences across this selection of cards. As expected the ever popular alfa AWUS036H demonstrates its superior capabilities, besting its nearest rival by an average of over 10dBm! Slightly unfortunately though, it hails from an earlier time and predates the wireless-N standard. For this reason it may interest some to look further than this otherwise clear winner (in the sensitivity department) if you require more than wireless-G. Each of the three remaining cards are wireless-N capable, but not dual band. A bit further down we reference an alfa dual band card (but as yet it is untested). In second place is the alfa AWUS036NEH. Perhaps surprisinigly, the NEH bests its larger and more powerful (transmit wise) sibling, the alfa AWUS036NH. The two cards utilize the same (RT3070) chipset and accordingly one might expect them to have very similar characteristics but this graph tells a different tale. The NEH seems to be the more sensitive card, being a clear 6dBm (4x) more sensitive than the NH. Let us not neglect the fact however that the larger NH is twice as powerful on the transmit side. In last place we find the TL-WN722N from TP-Link.
The chart above shows the relative differences between the four different antennas that were used in the tests. All four tests were done using the AWUS036H. The four (omni rubber-duck) antennas are
- the 4dbi antenna that shipped with the TL-WN722N
- the 5dbi antenna that ships standard with many of the alfas
- a d-link 7dbi antenna
- an alfa branded 9dbi antenna
As might be expected, the antenna size differences in this test had a smaller overall effect than the differences between the cards themselves.
The above chart is a duplicate of the first one on this page, but with the test laptop’s internal Centrino wireless-N 1000 card’s results overlayed as well. This way we can see the relative differences between that (default) card and the others. As shown, it actually does slightly better overall than the TL-WN722N! However, it is important to note here that sensitivity is not the only factor to consider in these tests. Transmit power is just as important an indicator, and in this respect the TL-WN722N is significantly better with 100mW transmit power as compared to the Centrino’s meagre 25mW. The alfas are the clear winners in this round however, with the 1000mW of the AWUS036H and AWUS036NEH, and 2000mW of the AWUS036NH.
In fact transmit power could be the deciding factor in many people’s decisions of which card to use. If two way communication is required it is not enough that your card is able to “hear” many accesspoints. It is imperative also that it is able to “be heard” in order to communicate. It is likely that many of these cards are sensitive enough that they are able to “hear” more accesspoints than are able to “hear” them. And so transmit power might become a critical factor in one’s purchasing decision. In the next part of this article we will look more specifically at the importance of transmit power.
The above table lists the cards’ sensitivity and transmit power according to their respective manufacturers’ websites.
These tests were performed using Kali linux version 1.0.6 64 bit iso, by collecting two sets of 200 data samples for each card/antenna combination in a round robin fashion and then keeping only the intersection of each set. This means in other words that for an access point to be counted as “detected” by the card/antenna combination it had to be detected in both instances of the testing. The samples were collected by active probe via the command iwconfig. For the purposes of this test, each access point’s data was then averaged to find the mean signal level detected. Each test was carefully controlled and as close as possible to identical to the others. The only difference was the time at which each test occurred.
All three alfas detected a similar number of access points, with the TP-Link (and the internal Centrino card) detecting significantly fewer:
- AWUS036H (43)
- AWUS036NEH (43)
- AWUS036NH (44)
- TL-WN722N (33)
- Centrino internal (32)
Three other cards from alfa, which we have as yet not tested here but which nonetheless may be worth keeping in mind as we have seen positive reports as to their functionality in linux for penetration testing with kali linux are
which are all wireless-N capable cards. The AWUS051NH is also 5GHz capable.