What is the difference between a physical channel and a logical channel?
The Physical channels are determined by the timeslot, whereas the logical channels are determined by the information carried within the physical channel. These channels may either be used for user data (payload) or signalling to enable the system to operate correctly.
How many logical channels are there in LTE?
Uplink Logical Channel : In Uplink we have 2 control channels and one traffic channel.
What are the different types of logical channels?
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 are logical channels in LTE?
Logical channels define what type of data is transferred. These channels define the data-transfer services offered by the MAC layer. Data and signalling messages are carried on logical channels between the RLC and MAC protocols. Logical channels can be divided into control channels and traffic channels.
What are the logical channels in GSM in mobile computing?
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 a GSM structure or architecture Mcq?
These are the broadcast channel (BCH), the common control channel (CCCH) and the dedicated control channel (DCCH). Each control channel consists of several logical channels.
What is channel mapping in LTE?
LTE transport channels Broadcast Channel (BCH) : The LTE transport channel maps to Broadcast Control Channel (BCCH) Downlink Shared Channel (DL-SCH) : This transport channel is the main channel for downlink data transfer. It is used by many logical channels. Paging Channel (PCH) : To convey the PCCH.
What is GSM logical channel?
Why are so many logical channels used in GSM?
GSM needs to transmit a large amount of signalling information apart from the payload data. These different types of data are transmitted via several logical channels. The name stems from the fact that each of the data types is transmitted on specific timeslots that are parts of physical channels.
Which protocol does the mapping between logical channels and transport channels?
The MAC layer is responsible for mapping between logical channels and transport channels, multiplexing and demultiplexing of upper layer PDUs, scheduling air interface resources in both uplink and downlink, error correction through HARQ, priority handling between UEs by means of dynamic scheduling, and priority …
What are the different types of channels 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 main parts of a mobile station in a GSM network Mcq?
In GSM, a mobile station consists of four main components: Mobile termination (MT) – offers common functions such as: radio transmission and handover, speech encoding and decoding, error detection and correction, signalling and access to the SIM. The IMEI code is attached to the MT.
How are logical and transport channels used in LTE?
LTE uses a series of data channels to provide effective management of the data: physical, logical and transport channels are used. These LTE channels provide different interfaces into the higher layers of the protocol stack and in this way they are able to provide efficient management of the data.
How are logical channels served in priority order?
The logical channels are then served in decreasing priority order up to their prioritized data rate, which avoids starvation as long as the scheduled data rate is at least as large as the sum of the prioritized data rates.
How to perform logical channel prioritization ( LCP )?
There is provided a method for performing a logical channel prioritization. The method may comprise: receiving an uplink (UL) grant; identifying a set of logical channels whose data are to be transmitted using the uplink grant; and performing a logical channel prioritization (LCP) based on the identified set of logical channels.
How is per terminal scheduling used in LTE?
Using radio-bearer-specific scheduling grants would increase the control signaling overhead in the downlink and hence per-terminal scheduling is used in LTE. The simplest multiplexing rule would be to serve logical channels in strict priority order.