In a packet-based communications network, packet aggregation is the process of joining multiple packets together into a single transmission unit, in order to reduce the overhead associated with each transmission.

Packet aggregation is useful in situations where each transmission unit may have significant overhead (preamble

Syncword

In computer networks, a syncword, sync character or preamble is used to synchronize a transmission by indicating the end of header information and the start of data.-Examples:For example an audio receiver is receiving a bit stream of data...

s, headers, cyclic redundancy check

Cyclic redundancy check

A cyclic redundancy check is an error-detecting code commonly used in digital networks and storage devices to detect accidental changes to raw data...

, etc.) or where the expected packet size is small compared to the maximum amount of information that can be transmitted.

In a communication system based on a layered OSI model

OSI model

The Open Systems Interconnection model is a product of the Open Systems Interconnection effort at the International Organization for Standardization. It is a prescription of characterizing and standardizing the functions of a communications system in terms of abstraction layers. Similar...

, packet aggregation may be responsible for joining multiple MSDU

MSDU

MAC service data unit or MSDU stands for MAC Service Data Unit.The MSDU is the service data unit that is received from the logical link control sub-layer which lies above the medium access control sub-layer in a protocol stack. The LLC and MAC sub-layers are collectively referred to as the DLL.-...

s into a single MPDU

MPDU

MAC protocol data unit or MPDU is a message exchanged between MAC entities in a communication system based on the layered OSI model....

 that can be delivered to the physical layer

Physical layer

The physical layer or layer 1 is the first and lowest layer in the seven-layer OSI model of computer networking. The implementation of this layer is often termed PHY....

 as a single unit for transmission.

The ITU-T

ITU-T

The ITU Telecommunication Standardization Sector is one of the three sectors of the International Telecommunication Union ; it coordinates standards for telecommunications....

 G.hn

G.hn

G.hn is the common name for a home network technology family of standards developed under the International Telecommunication Union's Standardization arm and promoted by the HomeGrid Forum...

 standard, which provides a way to create a high-speed (up to 1 Gigabit/s) Local area network

Local area network

A local area network is a computer network that interconnects computers in a limited area such as a home, school, computer laboratory, or office building...

 using existing home wiring (power lines

Power line communication

Power line communication or power line carrier , also known as power line digital subscriber line , mains communication, power line telecom , power line networking , or broadband over power lines are systems for carrying data on a conductor also used for electric power transmission.A wide range...

, phone lines and coaxial cables

Ethernet over coax

Ethernet over Coax is a family of technologies that supports the transmission of Ethernet frames over coaxial cable.- History :The first Ethernet standard, known as 10BASE5 in the family of IEEE 802.3, specified baseband operation over coaxial cable...

), is an example of a protocol that employs packet aggregation to increase efficiency.