Don't be confused when any Sales person says you will get 100Mbps over WIRELESS or WiFi ...as it's actually NOT TRUE.
As Wifi is dependent of many factors and that 802.11G (Normal WiFi such as iphones and smart tabs) are limited to the 2.4Ghz frequency and technically LIMITED to 54Mbps One Way, usually you will get about 15-20Mbps Maximum at best at 3m range whereas the WiFi-N or 802.11N uses the 5.Ghz band and on top of that 40Mhz bandwidth slots within the 802.11G (which uses 20Mhz slots).
Technically, it could go as far as 100+ but you will only see 45-60Mbps range and it's much better with newer HDB BTO Flats as they can pass thru the walls better.... being higher in power.
If your package is 100Mbps...then you need at least a Fast Ethernet (FE) Lan card connected to the wire which will let you push thru 92-100mbps or Gigabit Ethernet (GBE) port for up to 1000Mbps
Dual Bands or what not.. we are sorry you are misled by the sales person. Be it SingTEL or MyRepublic... they don't know much other what they were told from those up there. Here...we are down to earth.
To check your WiFi connection... we recommend using Xirrus WiFi inspector... anything more than -60dbm is BAD... (less than ONE BAR) as you get up to only 10mbps.