5 Difference Between Soft Hand Off And Hard Hand Off

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What Is Soft Hand-off?

Soft handoff refers to the overlapping of repeater coverage zones, so that every cell phone set is always well within range of at least one repeater (also called a base station). In some cases, mobile sets transmit signals to, and receive signals from, more than one repeater at a time.

Soft handoff technology is used by code-division multiple access (CDMA) systems. Older networks use frequency division multiplex (FDM) or time division multiplex (TDM). In CDMA, all repeaters use the same frequency channel for each mobile phone set, no matter where the set is located. Each set has an identity based on a code, rather than on a frequency (as in FDM) or sequence of time slots (as in TDM). Because no change in frequency or timing occurs as a mobile set passes from one base station to another, there are practically no dead zones. As a result, connections are almost never interrupted or dropped.

What You Need To Know About Soft Hand Off

  • Soft hand-off is where a new connection is established before old one is released.
  • It allocates same frequency.
  • Soft hand-off is used in CDMA and in some TDMA systems.
  • It is more complex than hard hand-off.
  • Soft hand-off handsets communicates up to three or four radio links at the same frequency.

What Is Hard Hand-off?

A hard handoff is a handoff technique used with cellular networks that requires the user’s connection to be entirely broken with an existing base station before being switched to another base station. It enables mobile/cellular service providers to provide continuous service to users, especially when they are moving away from the connected base station/cell toward another base station/cell. A hard handoff is also known as a hard handover or break-before-make handover.

A hard handoff is primarily implemented when the subscriber/user is being connected to a base station with a different radio frequency than the current base station. All intra-frequency handovers/handoffs are types of hard handoffs.

A hard handoff is generally implemented in FDMA and TDMA based cellular networks and is more suited for applications/services that can afford a slight delay such as Internet, VoIP and WiMAX. However, a hard handoff is generally fast enough that user don’t feel an interruption or breakage in service. Moreover, unlike soft handovers that have multiple simultaneously connected channels, a hard handover is cheaper because it requires only one channel to operate.

What You Need To Know About Hard Hand Off

  • Hard hand-off is one where an existing connection must be broken when the new one is established.
  • It allocates different frequency.
  • Hard hand-off is typically used in TDMA and FDMA.
  • Less complex when compared to soft hand-off.
  • Hard hand-off  communicates with one BS at a time.

Also Read: Difference Between Hand Off And Hand Over

Difference Between Soft Hand Off And Hard Hand Off In Tabular Form

BASIS OF COMPARISON SOFT HAND OFF HARD HAND OFF
Description Soft hand-off is where a new connection is established before old one is released.   Hard hand-off is one where an existing connection must be broken when the new one is established.  
Frequency It allocates same frequency.   It allocates different frequency.  
Use Soft hand-off is used in CDMA and in some TDMA systems.   Hard hand-off is typically used in TDMA and FDMA.  
Complexity It is more complex than hard hand-off.   Less complex when compared to soft hand-off.  
Communication Soft hand-off handsets communicates up to three or four radio links at the same frequency.   Hard hand-off  communicates with one BS at a time.