In: Computer Science
WiMax networks are built around the IEEE 802.16 protocol.
Explain how calls are handed off between cells.
WiMax networks are built around the IEEE 802.16 protocol:
Answer: (a) True
Description:
WiMax - Worldwide Interoperability for Microwave Access network comes in a group or family of broadband wireless communications standards. It is based on the IEEE 802.16 protocol.
Explain how calls are handed off between cells:
Handoff:
• A handoff or handover is the process of transferring an active call or ongoing call from one channel or cell to another channel or cell in connected network.
• Handoffs which are well-implemented provide uninterrupted service in a communication network to a caller or user.
Two types of Handoffs:
(1) Hard Handoff:
• In a hard handoff category, when the process of switching from one cell or base station to another occurs then an actual break in the connection happens. Before connecting a link to another cell, firstly radio link from the existing cell is broken but it is so quick that it cannot be noticeable by user.
• This procedure or policy is known as “break before make” policy. Hard handoff is sometimes also called inter-frequency handoff.
(2) Soft Handoff:
• In a soft handoff category, there is no break occurs while switching from one cell or base station to another. In this method, at least one of the links is always kept secured while adding or removing other radio links.
• This procedure or policy is known as “make before break” policy. Soft handoffs are generally established in co-located network sites.
Situations of Handoff triggering:
• An interference of calls with same frequency.
• A user with ongoing calls moves to another coverage cell.
• Transferring the services from one large micro-cell to another small micro-cell or vice versa.
• The number of subscribers or users of a particular cell reaches to its maximum capacity value.