[B.A.T.M.A.N.] about batman performance

["zb1981gm"<zb80211@gmail.com>]

I have used batman on my project for several months.It performs very well,stable especially! 
But,actually,I am not satisfied with the performance of Batman.I found that the bandwidth would drop sharply with the wireless hop increase. 
Now I provide my test result here: 

routerA and routerB is composed of compex wp543ahv mainboard (AR7161 platform) and two AR9220 wireless card.Firmware is Openwrt backfire. 
one card is working on 2.4G channel as AP mode,the other is working on 5G channel as mesh backbone  
batman version:2.0 
notebook1 and notebook2 is equiped with 802.11n usb wireless card which access to the AP mode card of routerA and routerB 

            channel 1                 channel 36              channel 11 
notebook1 ---------------  routerA --------------  routerB -------------- notebook2 

I use iperf to test bandwidth 

notebook1 ----------- routerA    45Mbps 
routerA   ----------- routerB    46Mbps 
routerB   ----------- notebook2  45Mbps 

But the bandwidth between notebook1 and notebook2 remains 8Mbps 
bandwidth between notebook1 and routerB remain 18Mbps 

So the conclution is that the bandwidth will be halfed with the 1 hop increase! right? 

I also found that the interface alternating mode and bonding mode doesn't take effect 

              channel 1 
routerA  ------------------  routerB 
              channel 36 

The test result is no difference whatever I configured alternating or bonding or just single radio 

According to the batman official site, alternating or bonding mode would improve the performance compared with the single radio mode 

looking forward  somebody's help 
highly appreciated!