Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

From GSM to LTE Advanced Pro and 5G > GPRS And EDGE > Flashcards

GPRS And EDGE Flashcards

1
Q

What does GPRS mean ?

A

General Packet Radio Service

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What does EDGE mean ?

A

Enhanced Data rates for GSM Evolution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the advantages of packet Switching transmission over GPRS ?

A
  • By flexibly allocating bandwidth on the air interface, GPRS exceeds the slow datarates of GSM circuit‐switched connections of 9.6 or 14.4 kbit/s. Datarates of up to 170 kbit/s are theoretically possible. Multislot class 10 mobile devices (see next bullet) reach speeds of about 85 kbit/s and are thus in the range of the fixed‐line analog modems that were in widespread use at the time GPRS was introduced.
  • With the EDGE update of the GSM system, further speed improvements were made. The enhancements of EDGE for GPRS are called EGPRS in the standards. The term, however, is not widely used in practice and preference has been given to the term EDGE. With an EDGE class 32 mobile device, it is possible to reach transmission speeds of up to 270 kbit/s.
  • GPRS is usually charged by volume and not by time, as shown in Figure 2.3. For subscribers this offers the advantage that they pay for downloading a web page but not for the time spent reading it, as would be the case with a circuit‐switched connection. For the operator of a wireless network it offers the advantage that the scarce resources on the air interface are not wasted by ‘idle’ data calls because they may be used for other subscribers.
  • GPRS significantly reduces call set‐up time. Similar to a fixed‐line analog modem, a GSM circuit‐switched data call took about 20 seconds to establish a connection with the Internet service provider, while GPRS accomplishes the same in less than 5 seconds.
  • Since the subscriber does not pay for the time when no data is transferred, the call does not have to be disconnected to save costs. This is called ‘always on’ and enables applications like e‐mail programs to poll for incoming e‐mails in certain intervals or allows messaging clients to wait for incoming messages.
  • When the subscriber is moving, by train for example, the network coverage frequently becomes very bad or is even lost completely for some time. When this happens, circuit‐switched connections are disconnected and have to be reestablished manually once network coverage is available again. GPRS connections, on the other hand, are not dropped, as the logical GPRS connection is independent of the physical connection to the network. After coverage is regained, the interrupted data transfer simply resumes.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

In GPRS, what is the smallest radio resource unit that may be assigned to à mobile station ?

A

A block of four bursts of a Packet Data Traffic Channel (PDTCH).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What does PDTCH mean?

A

Packet Data Traffic Channel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How many frames are in a GPRS multiframe ?

A

52

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the special frames in a GPRS multiframe ?

A
  • Frames 24 and 51: used to allow the mobile device to perform signal strength measurements on neighboring cells.
  • Frames 12 and 38: used for timing advance calculations.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the GPRS timeslot aggregation / multislot ?

A

It is the allocation of several consecutive PDTCH timeslots to a single subscriber (to increase the transmission speed)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the mobile device multislot class ?

A

It is the a number that tells how many consecutive timeslots the mobile device can support in downlink, in uplink and simultaneously.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How does the network know how many timeslots the mobile device supports ?

A

The device has to inform the network of its capabilities. This so‐called ‘mobile station classmark’ also contains other information such as ciphering capabilities.

The classmark information is sent every time the mobile device accesses the network.

It is then used by the network together with other information such as available timeslots to decide how many of them may be assigned to the user.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is a GPRS coding scheme ?

A

It is the method used to add error detection and correction to the data before it is sent over the air.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How many GPRS coding scheme are defined ?

A

4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

List the GPRS coding scheme with their characteristics ?

A

Name - Number of user data bits per block (4 bursts) - transmission speed per timeslot

CS1 - 160 - 8 kbps
CS2 - 240 - 12 kbps
CS3 - 288 - 14.4 kbps
CS4 - 400 - 20 kbps

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How does CS4 coding scheme realize such a good debit ?

A

CS‐4 does not add any redundancy to the data. Therefore, CS‐4 may only be used when the signal quality between the network and the mobile device is very good.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is puncturing ?

A

The use of the convolutional coding in CS‐2 and CS‐3 results in more coded bits than may be transmitted over a radio block.

To compensate for this, some of the bits are simply not transmitted; this is called ‘puncturing.’

As the receiver knows which bits are punctured, it may insert 0 bits at the correct positions and then use the convolutional decoder to recreate the original data stream. This, of course, reduces the effectiveness of the channel coder as not all the bits that are punctured are 0 bits at the sender side.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What did EDGE bring new ?

A

A new Modulation: 8-PSK

New coding schemes: from MCS1 to MCS9

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What does 8PSK mean ?

A

8 Phase Shift Keying

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the maximum data rates allowed by EDGE ?

A

60kbps

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How is the mobile device informed about the EDGE capability of the network ?

A

The mobile device is informed of the EDGE capability of a cell by the EDGE capability bit in the GPRS cell options of the System Information 13 message, which is broadcast on the Broadcast Common Control Channel (BCCH)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How is the network informed about the EDGE capability of the mobile device ?

A

The network is informed of the mobile device’s EDGE capability during the establishment of a new connection.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What does BEP mean ?

A

Bit Error Probability

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How is the BEP used ?

A

BEP is used to make the network able to do a precise use of the best modulation and coding for the current radio conditions. This is done in the mobile device by continuously calculating the current bit error probability (BEP) and reporting the values to the network. The network in turn may then adapt its current downlink modulation and coding to the appropriate value.

For the uplink direction, the network may measure the error rate of data that was recently received and instruct the mobile device to change its MCS accordingly.

As both network and mobile device may report the BEP very quickly, it is also possible to adapt quickly to changing signal conditions, especially when the mobile device is in a moving car or train. This reduces the error rate and ensures the highest transmission speed in every radio condition.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the techniques used in EDGE to manage transmission errors that were not recovered by the convolution decoder ?

A
  • Incremental Redundancy

- Re-segmentation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Describe the incremental redundancy technique ?

A

Some error detection and correction bits produced by the convolutional decoder are punctured and therefore not put into the final block that is sent over the air interface. With the incremental redundancy scheme it is possible to send the previously punctured bits in a second or even a third attempt.

On the receiver side, the original block is stored and the additional redundancy information received in the first and second retry is added to the information. Usually only a single retry is necessary to allow reconstruction of the original data based on the additional information received.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Describe the resegmentation technique ?

A

It is a way of retransmitting faulty blocks that consist in splitting them up into two blocks for a retransmission that uses a different MCS (with more redundancy for error correction)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

List some situations where signaling data need to be exchanged in GPRS

A

The network pages the mobile device to inform it of incoming packets

The mobile device accesses the network to request resources (PDTCHs) to send packets

Modification of resources assigned to a subscribe and acknowledgment of correct reception of user data packets.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is the re segmentation technique ?

A

It is a retransmission technique of errorneous packets consisting in spliting that Packet in 2 and send the 2 parts with more redunded coding scheme.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

How many network mode of operations exists in GPRS ?

A

2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Describe the NOM1 (Network Opetations Mode 1)

A

Gs Interface is used to transfer Paging messages when data communications is ongoing at the same time.

The Gs interface connect the MSC with the SGSN

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What does SGSN mean ?

A

Serving GPRS Support Node

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What does GGSN mean ?

A

Gateway GPRS Support Node

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What does PACCH mean ?

A

Packet Associated Control CHannel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Describe the GPRS NOM2 (Network Opetations Mode 2)

A

Simpler than NOM1.

No Gs Interface.

To overcome the shortcoming of not being able to signal incoming SMS and voice calls during a GPRS data transfer between the circuit‐switched and packet‐switched core network, a method has been defined for the BSC in the radio network to inform the GPRS Packet Control Unit (PCU) is ongoing, the PCU will send the Paging message during the data transfer to the mobile device. The data transfer may then be interrupted, and the mobile device may respond to the paging message from the MSC.

To inform mobile devices which of the two GPRS network modes is used, GPRS uses the GSM BCCH channel and the SysInfo 13 message.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What does PCU mean ?

A

Packet Control Unit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What are the GSM channels that are shared by the GPRS ?

A

BCCH
RACH
AGCH
PCH

36
Q

What are the channels specific to GPRS ?

A
  • PDTCH: Packet Data Traffic CHannel
  • PACCH: Packet Associated Control CHannel
  • PTCCH: Packet Timing Control CHannel
37
Q

What does NACC mean ?

A

Network Assisted Cell Change

38
Q

What are the 3 states of a GPRS Mobile Device ?

A

Idle
Ready
Standby

39
Q

List 3 advantages of circuit switched data transmission over GSM.

A
  • Data that is sent does not need to contain any signaling information such as information about the destination. Every bit simply passes through the established channel to the receiver.
  • The circuit‐switched channel has a constant bandwidth, the sender does not have to worry about a permanent or temporary bottleneck in the communication path.
  • Circuit‐switched connections have a constant delay time.
40
Q

What is the “GPRS Always On” ?

A

Since the subscriber does not pay for the time when no data is transferred, the call does not have to be disconnected to save costs. This is called ‘always on’ and enables applications like e‐mail programs to poll for incoming e‐mails in certain intervals or allows messaging clients to wait for incoming messages.

41
Q

Which debit can be reached by a GPRS Multislot class 10 mobile devices ?

A

85kbps

42
Q

Which debit can be reached by an EDGE class 32 mobile device ?

A

270kbps

43
Q

Why does GPRS only support IP packet switching ?

A

GPRS was initially designed to support different types of packet‐switching technologies. The great success of the Internet, which uses the IP exclusively for packet switching, has led to IP being the only supported protocol today.

44
Q

Why can we say that GPRS bandwidth is asymmetric?

A

Because for many multislot classes of devices the maximum number of consecutive timeslots that can be allocated in uplink is lesser than the maximum number of consecutive timeslot to allocate on downlink.

For web browsing it is OK.

45
Q

What is the “mobile station classmark”

A

It is the set of capabilities of a mobile device including its GPRS multislot class, its ciphering capabilities, etc.

The classmark information is sent every time the mobile device accesses the network. It is then used by the network together with other information such as available timeslots to decide how many of them may be assigned to the user. The network also stores the classmark sent in the uplink direction and is thus able to assign resources in the downlink direction immediately, without asking the mobile device for its capabilities first.

46
Q

What are the options operators have to allocate TCH and PDTCH on the carrier ?

A

The air interface must be shared between GSM and GPRS. Therefore, the maximum GPRS datarate decreases as more GSM voice/data connections are needed.

Timeslots may be assigned statically, which means that some timeslots are reserved for GSM and some for GPRS. The operator also has the option of dynamically assigning timeslots to GSM or GPRS. If there is a high amount of GSM voice traffic, more timeslots may be used for GSM. If voice traffic decreases, more timeslots may be given to GPRS. It is also possible to assign a minimum number of timeslots for GPRS and dynamically add and remove timeslots depending on voice traffic.

47
Q

What are the main characteristics of a GPRS coding scheme ?

A

It’s name (CS-X)

The number of user data bits per block (four bursts with 114 bits each)

The transmission speed per timeslot (kbit/s)

48
Q

How to compute the average debit per timeslot?

A

(Number of bits transmitted per timeslot * number of effective data frames in a multiframe) / (number of total frames in a multiframe * 4615)

49
Q

Which differences exists between GSM/GPRS and EDGE ?

A
  • The transmission modulation: GMSK for GPRS and 8-PSK for Edge
  • The coding schemes: CS1 to CS4 on GPRS and MCS1 to MCS9 for Edge
  • Incremental Redundancy and Resegmentation techniques in Edge
50
Q

Which speed per timeslot can be reached by EDGE ?

A

60kbps

51
Q

How the interleaving algorithm adapt to the 3 scenarios: voice over GSM, Data over GSM (fax) or encrypted voice, Edge ?

A

Voice Over GSM: the interleaving algorithm will spread 456bits (4 bursts) over 8 bursts.

Data over GSM (fax) or encrypted voice: as errors cannot be tolerated the spreading is done over more (than 8) bursts.

Edge: As EDGE notably increases the number of bits that may be sent in a burst, it has been decided to decrease the block size for MCS‐7, MCS‐8, and MCS‐9 to fit in two bursts instead of four.

52
Q

How many device classes are defined by the GPRS Standard ?

A

3

A, B and C

53
Q

What is the Gs Interface?

A

It is the interface between the circuit‐switched part (MSC) and the packet‐switched part (Serving GPRS Support Node – SGSN).

54
Q

What is the Gb interface ?

A

The Gb interface is the interface between the PCU and the SGSN

55
Q

What is the function of the PDTCH ?

A

To send user data across the air interface

56
Q

What is the function of the PACCH ?

A

These are necessary to acknowledge packets that are transported over the PDTCH. When a mobile device receives data packets from the network via a downlink PDTCH, it has to acknowledge them via the uplink PACCH.

In addition, the PACCH is used for signaling messages that assign uplink and downlink resources.

57
Q

What is the function of the PTCCH ?

A

This channel is used for timing advance estimation and control of active mobile devices. To calculate the timing advance, the network may instruct an active mobile device to send a short burst at regular intervals on the PTCCH. The network then calculates the timing advance and sends the result back in the downlink direction of the PTCCH.

58
Q

Describe the GPRS idle state

A

In this state, the mobile device is not attached to the GPRS network at all. This means that the SGSN is not aware of the user’s location, no Packet Data Protocol (PDP) context is established, and the network may not forward any packets for the user.

59
Q

Describe the GPRS Ready state

A

When the user wants to attach to the GPRS network, the mobile device enters the ready state as soon as the first packet is sent. While in ready state, the mobile device has to report every cell reselection to the network so that the SGSN may update the user’s position in its database; this process is called ‘cell update.’

Being in ready state simply means that both signaling and possibly user data may be sent to the mobile device without prior paging by the network.

60
Q

Describe the NACC procedure

A

The mobile device send a Packet Cell Change Notification message to the network when it wants to change into a different cell. The network responds with a Packet Neighbor Cell Data message, alongside the ongoing user data transfer, that contains all necessary parts of the system information of the new cell to allow performance of a quick reselection.

Subsequently, the network stops the user data transfer in the downlink direction and instructs the mobile device to switch to the new cell. The mobile device then moves to the new cell and reestablishes the connection to the network without having to read the system information messages from the broadcast channel first. By skipping this step, the data traffic interruption is reduced to a few hundred milliseconds.

61
Q

Describe the GPRS standby state

A

In this state, the mobile device only informs the network of a cell change if the new cell belongs to a routing area different from the previous one. If data arrives in the network for the mobile device after it has entered the standby state, the data needs to be buffered and the network has to page the subscriber in the complete routing area to get the current location. Only then may the data be forwarded.

The advantage of the standby state for the network is the reduced signaling overhead as not every cell change has to be reported. Thus, scarce resources on the RACH, the AGCH, and the PDTCH may be saved. For the mobile device, the advantage of the standby state is that it may stop the continuous monitoring of the AGCH and only infrequently monitor the PCH, as described

62
Q

Describe the PCU

A

Packet Control Unit.

It is the packet‐switched counterpart of the BSC.

63
Q

What are the functions of the PCU ?

A

assignment of timeslots to subscribers in the uplink direction when requested by the mobile device via the RACH or the PRACH;

assignment of timeslots to subscribers in the downlink direction for data arriving from the core network;

flow control of data in the uplink and downlink directions and prioritization of traffic;

error checking and retransmission of lost or faulty frames; subscriber paging;

and supervising entity for subscriber timing advance during data transmission.

64
Q

What is the SGSN

A

Serving GPRS Support Node

It is the packet‐switched counterpart to the MSC in the circuit‐switched core network. It is responsible for user plane management and the signaling plane management.

65
Q

Which component of the Network is in charge of the encryption in the GPRS ?

A

The SGSN

66
Q

What is the GGSN ?

A

Gateway GPRS Support Node

The GGSN connects the GPRS network to the external data network. The external data network will, in most cases, be the Internet. For business applications, the GGSN may also be the gateway to a company intranet.

The GGSN is also involved in setting up a PDP context. In fact, the GGSN is responsible for assigning a dynamic or static IP address to the user. The user keeps this IP address while the PDP context is established.

67
Q

What is a GPRS Radio Link Control/Medium Access Control (RLC/MAC) frame ?

A

It is a block, which consists of four bursts on one timeslot on the air interface for GPRS and two bursts for EDGE MCS 7–9.

68
Q

What does TBF mean ?

A

Temporary Block Flow

69
Q

What does USF mean ?

A

Uplink State Flag

70
Q

Which GPRS interface is not standardised and what are the implications?

A

The interface BSC - PCU.

It implies that these 2 devices must come from the same vendor.

71
Q

What does SNDCP mean ?

A

SubNetwork Dependent Convergence Protocol

72
Q

List the GPRS interfaces

A 
The Abis Interface (BTS <-> BSC <-> PCU)
The Gb Interface (PCU <-> SGSN)
The Gn Interface (SGSN <-> GGSN)
The Gi Interface (GGSN <-> Internet / Destination Network)
The Gr Interface ( SGSN <-> HLR )
The Gc Interface (GGSN <-> HLR)
The Gp Interface (Roaming SGSN <-> Home GGSN)
The Gs Interface (SGSN <-> MSC/VLR)
73
Q

Describe the Abis Interface

A

It is the interface between BTS and BSC and goint onto the PCU. (Because for GPRS, the BSC is almost transparent)

The protocol stack from the bottom to the top is :

E1/Ethernet/Fiber 
MAC
RLC
LLC
SNDCP
User Data
74
Q

What is a TBF ?

A

Temporary Block Flow

A TBF identifies data to or from a user for the time of the data transfer.

Temporary Block Flow (TBF) is a connection established between a Mobile Station (MS) and a Base Station (BS) to enable packet exchanges between the BS and MS entities in GPRS networks.

A Temporary Block Flow (TBF) is a physical connection used by the two RR entities to support the unidirectional
transfer of LLC PDUs on packet data physical channels. The TBF is allocated radio resource on one or more PDCHs
and comprise a number of RLC/MAC blocks carrying one or more LLC PDUs. A TBF is temporary and is maintained
only for the duration of the data transfer.

75
Q

What is a TFI ?

A

Each TBF is assigned a Temporary Flow Identity (TFI) by the network. The assigned TFI is unique among concurrent TBFs in each directions and is used instead of the MS identity in the RLC/MAC layer. The same TFI value may be used concurrently for TBFs in opposite directions. The TFI is assigned in a resource assignment message that precedes the transfer of LLC frames belonging to one TBF to/from the MS. The same TFI is included in every RLC header belonging to a particular TBF as well as in the control messages associated to the LLC frame transfer (e.g. acknowledgements) in order to address the peer RLC entities.

76
Q

What is the function of a USF ?

A

Uplink State Flag

As a timeslot in GPRS may not be used exclusively by a single subscriber, a mechanism is necessary to indicate to a mobile device when it is allowed to send on the timeslot. Therefore, the uplink assignment message contains a parameter called the Uplink State Flag (USF). A different USF value is assigned to every subscriber that is allowed to send on the timeslot.

To know when it may use the uplink timeslots, the mobile device has to listen to all the timeslots it has been assigned in the downlink direction. Every block that is sent in the downlink to a subscriber contains a USF in its header. It indicates who is allowed to send in the next uplink block.

77
Q

What is the timing advance Control (description) ?

A

The farther a mobile device is away from a BTS, the sooner it has to start sending its data bursts to the network in order for them to arrive at the BTS at the correct time. As the position of the user may change during the data exchange, it is necessary for the network to constantly monitor how far away the user is from the serving base station. If the user moves closer to the BTS, the network has to inform the mobile device to delay sending its data compared to the current timing. If the user moves farther away, it has to start sending its bursts earlier. This process is called timing advance control.

78
Q

What are the functions of the GPRS Radio Resource (RR) Management ?

A
  • Assignment of TBF (Temporary Block Flows) in uplink direction
  • Assignment of TBF (Temporary Block Flows) in downlink direction
  • Timing Advance Control
79
Q

Describe the TBF management in uplink direction

A

When the Mobile Station want to send data on the uplink, it request for resources via the RACH/PRACH. The PCU answers with an immediate assignment message on the AGCH. That message contains the timeslots on which the MS is allowed to send data.
As a timeslot in GPRS can be shared among multiple MS, the assignment message also contains a parameter called USF (Uplink State Flag), that is different for every subscriber allowed to send on the same timeslot.

To know when it may use the uplink timeslot, the MS listen to all the timeslots assigned to him in downlink, if the header of a block contains its USF (received in the assigment message), it indicate that the MS is allowed to send in the next uplink block. This procedure is referred to as ‘dynamic allocation’.

The PCU will continue to assign uplink blocks to the MS until the MS will indicate it no longer require blocks. This is done using a 4-bit countdown value in the block headers sent by the MS in uplink. When this value reach 0, the PCU stop assigning blocks.

80
Q

Describe the TBF management in downlink direction

A

When the PCU receives packets to be sent to MS from the SGSN, it will send a packet downlink assignment message to the MS via the AGCH (or the PACGH). That message contains the TFI (temporary Flow Identity) of a TBF and the timeslots the MS has to monitor.

The MS can then immediately start to monitor these timeslot. It will be interested only by the messages having the same TFI that was assigned to him by the PCU. Once the PCU has sent all data in its queue, it will set the ‘final block indicator’ bit in the last block so that the MS stops listening on the timeslots.

81
Q

In the GPRS 52 frames which frames are dedicated for timing advance ?

A

Frame 12 and 38.

PTCCH

82
Q

What are the functions of the LLC layer (Abis Interface) ?

A

Framing of the user data packets and signaling messages of the mobility management and session management of the SGSN.

Optionally, connection reliability management between the MS and the SGSN by using an acknowledgment mechanism for the correctly received blocks (acknowledge mode).

83
Q

What are the functions of the SNDCP layer (Abis Interface) ?

A

Framing IP User Data to send it over the radio network.

Optionally, data compression.

84
Q

Describe the Gb Interface

A

The Gb Interface connects the PCU with the SGSN.

The protocol stack is:

E-1 | Ethernet
Frame Relay | IP
BSSGP
LLC
SNDCP
User Data
85
Q

What is BSSGP ?

A

BSSGP is a protocol used in the GPRS mobile packet data system. It denotes Base Station System GPRS Protocol. It transfers information between two GPRS entities SGSN and BSS over a BSSGP Virtual Connection (BVC). This protocol provides radio-related quality of service and routing information that is required to transmit user data between a BSS and an SGSN. It does not carry out any form of error correction.

86
Q

What are the primary functions of BSSGP ?

A

Provision by an SGSN to a BSS of a radio related information used by the RLC/MAC function in the download link.

Provision by a BSS to an SGSN of radio related information derived from the RLC/MAC function in the uplink.

Provision of functionality to enable two physically distinct nodes, an SGSN, a BSS, to operate node management control functions (QoS, flow control).

87
Q

Describe the Gn Interface ?

A

The Gn Interface connects the SGSNs with GGSNs

At the layer 3, the IP protocol is used (usually over either Ethernet, Ethernet on Optical Links / etc., etc.).

Above IP, there is the GTP (GPRS Tunneling protocol)

From GSM to LTE Advanced Pro and 5G (2 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions