Advantages of FHSS | disadvantages of FHSS

This page covers advantages and disadvantages of FHSS. It mentions FHSS advantages or benefits and FHSS disadvantages or drawbacks. It also describes FHSS basics.

What is FHSS?

Introduction:
• The term FHSS is the short form of Frequency Hopping Spread Spectrum.
• In this technique, carrier frequency used for modulation is varied by predefined PRS (Pseudonoise Random Sequence) generator. The PN sequence used is known to both the transmitter and receiver.
• The FHSS techniques are divided into two types viz. fast hopping and slow hopping. In fast hopping FHSS, hopping rate is higher compare to information rate. In slow hopping FHSS, hopping rate is slower compare to information rate.
• Information bits are carried by different frequencies.
• FHSS delivers capacity of about 3 Mbps.
• It is very robust technology.
• It is used for point to multipoint scenario.

The figure-1 depicts FHSS transmitter and FHSS receiver block diagrams.

Benefits or advantages of FHSS

Following are the benefits or advantages of FHSS:
➨It provides very robust transmission path in the presence of interferences such as multipath, noise and other wireless transmissions etc. due to support of wide bandwidth.
➨It can be employed in point to multipoint applications.
➨It supports about ten nearby WLAN compliant APs (Access Points) without any significant interference issues.
➨It provides security against any kind of intrusion as only transmitter and receiver are aware of PN codes.

Drawbacks or disadvantages of FHSS

Following are the disadvantages of FHSS:
➨As FHSS relies on carrier frequencies to transmit information bits, it leads to strong bursty errors due to frequency selective fading mainly.
➨It supports lower data rate of 3 Mbps compare to 11 Mbps supported by DSSS.
➨It supports lower coverage range due to high SNR requirement at receiver.
➨The modulation scheme has become obsolete due to use of emerging wireless technologies in the wireless products.