What are logical channels?
A logical channel is defined by the type of information it carries and is generally classified as a control channel, used for transmission of control and configuration information necessary for operating an LTE system, or as a traffic channel, used for the user data.
What are the channel types used in UMTS?
The 3G UMTS transport channels include:
- Dedicated Transport Channel (DCH) (up and downlink).
- Broadcast Channel (BCH) (downlink).
- Forward Access Channel (FACH) (down link).
- Paging Channel (PCH) (downlink).
- Random Access Channel (RACH) (uplink).
- Uplink Common Packet Channel (CPCH) (uplink).
What are logical transport and physical channels?
Physical channels: These are transmission channels that carry user data and control messages. Logical channels: Provide services for the Medium Access Control (MAC) layer within the LTE protocol structure.
What is the difference between physical and logical channel?
Physical channels can be used to transmit speech, data or signalling information. A physical channel may carry different messages, depending on information that is to be sent. These messages are called logical channels.
What is logical channel prioritization?
Logical Channel Prioritization, LCP, procedure Based on the uplink transmission resource grant message signalled on the PDCCH, the UE has to decide on the amount of data for each logical channel to be included in the new MAC and, if necessary, also to allocate space for a MAC Control Element.
What is logical channel group in LTE?
With just a little modification of 3GPP description, LCG can be defined as “A group of Logical Channel which buffer status is being reported.” There are four LCGs being used in LTE and each of the group has it’s own ID from 0 to 3.
Which channels are used for downlink in GSM UMTS?
There are mainly five Downlink Logical Channel in GSM.
- Frequency correction channel (FCCH)
- Synchronous channel (SCH)
- Broadcast control channel (BCCH)
- Paging channel (PCH)
- Access granted channel (AGCH)
Which of the following channels are used for downlink GSM UMTS?
UMTS Transport channels
| UMTS/WCDMA Transport Channel | Function | Direction |
|---|---|---|
| Common packet channel(CPCH) | It is used as contention channel for bursty data | Uplink |
| Forward access channel(FACH) | It is used to transfer user data/control signalling messages | Downlink |
What are physical channels?
Physical channel : The physical channels are those which are closest to the actual transmission of the data over the radio access network / 5G RF signal. They are used to carry the data over the radio interface. The physical channels often have higher level channels mapped onto them of provide a specific service.
How many logical channels are there in LTE?
Different channels provide interfaces to the higher layers of the LTE protocol stack and enables an orderly and defined segregation of the data. There are three types of channels into which the various data channels are grouped.
What is logical and physical connections explain with example?
A physical topology is how they are actually interconnected with wires and cables. For example, in a shared Ethernet network that uses hubs rather than switches, the logical topology appears as if every node is connected to a common bus that runs from node to node.
What is Fach in UMTS?
Forward Access Channel. A UMTS transport channel that forms the downlink half of a transport channel pair known as the RACH (Random Access Channel) / FACH (Forward Access Channel) combination. It is used for downlink signalling and small quantities of data.
What are the basic channels available in GSM?
There are two main types of GSM channels viz. physical channel and logical channel. Physical channel is specified by specific time slot/carrier frequency.
What are the types of logical channels in a GSM architecture?
There are two types of GSM logical channels, called Traffic CHannels (TCH) and Control CHannels (CCH). Traffic channels carry digitally encoded user speech or user data and have identical functions and formats on both the forward and reverse link.
What are the types of logical channels in GSM architecture Mcq?
These are the broadcast channel (BCH), the common control channel (CCCH) and the dedicated control channel (DCCH).
What are logical connections?
Logical connectors are used to join or connect two ideas that have a particular relationship. These relationships can be: sequential (time), reason and purpose, adversative (opposition and/or unexpected result), condition.
What is logical connection in network?
A logical network is a portion of a physical network that connects two or more logical network interfaces or devices. A logical network interface or device is the software entity that is known by an operating system.
What is cell DCH?
DCH : You can call this state as ‘Normal traffic mode’. When you make any connection for traffic (e.g, voice call and data call), in most case you (UE/Network) establish DCH state and most of traffic (Voice data, packet data) are being transmitted and received in this stage.
What are the types of logical channels in a GSM structure or architecture?
In GSM logical channels (see Figure 7.4) are used to carry traffic and control information. There are three types of logical channels: traffic channels (TCHs), control channels (CCHs), and the cell broadcast channel (CBCH). The traffic channels are used to transmit user information (speech or data).
What is the difference between control channel and traffic channel?
Traffic channels carry digitally encoded user voice or user data and have identical formats of both forward link and reverse link. Control channels carry signal and synchronization commands between the base station and mobile station.