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WLS 708 Kris
GPRS & EDGE
Questions & Solutions
1. The migration platforms to 2.5G from the existing TDMA and GSM networks are the ______and ______.
a) EDGE
b) GPRS
c) IS-95B
d) a and b
e) None of the above
2. GSM voice and data services are Packet switched.
a) True
b) False
3. The greater speeds provided by the GPRS are achieved over the air interface of ______divided into______.
a) 200kHz; 8 timeslots
b) 400kHz; 4 timeslots
c) 30 kHz; 3 timeslots
d) 1.25 MHz, 8 time slots
e) None of the above.
4. The most commonly used Channel coding scheme for GPRS is ______.
a) CS-1
b) CS-3
c) CS-4
d) CS-2
e) None of the above
5. CS-2 enables a given time slot to carry data at 13.4 Kbps per time slot and higher speeds of 40.2 Kbps to 53.6 Kbps can be achieved if a single user has access to ______time slots.
a) Single
b) two
c) Three
d) Multiple
e) None of the above.
6. In GPRS the time slots are shared between number of users and at the instant when user is sending/receiving data, another user can use the timeslots simultaneously on the air interface.
a) True
b) False
.
7. GPRS is a packet switching data service over laid on the ______infrastructure, which is primarily designed for voice.
a) TDMA
b) GSM
c) CDMA
d) NA-TDMA
8. GPRS ______supports the simultaneous use of data and voice services and a user can hold a conversation and transfer GPRS data at the same time.
a) Class D
b) Class B
c) Class A
d) Class C
e) All of the above.
9. GPRS is ______in which a single MS can have different time slots in up link and down link.
a) Symmetric
b) Asymmetric
c) None of the above
10. GPRS air interface is built on the same foundations as the GSM air interface and this allows both GSM and GPRS to share the same______resources.
a) Data
b) Voice
c) RF
d) None of the above
11. When a given time slot is used for to carry GPRS-related data traffic or control signaling it is known as______.
a) PDCH.
b) PTCCH.
c) CCCH
d) PAGCH
12. Each radio block in PDCH occupies four______frames, such that 12 radio blocks are used in multiframe.
a) GSM
b) TDMA
c) CDMA
d) FDMA
13. Packet Access Grant Channel (PAGCH) is used by the network to assign resources to MS prior to packet transfer and is applicable in the downlink as well as the uplink.
a) True
b) False
14. The PACCH is permanently not assigned to any given resource rather than when information needs to be sent on the PACCH, part of the user data is preempted.
a) True
b) False
15. All PDTCH are ______either uplink or downlink corresponding to the asymmetric capabilities of GPRS
a) Bi-directional
b) Unidirectional
c) Omni directional
d) None of the above
16. ______is physically integrated with the BSC and is a logical network element that is responsible for a number of GPRS related functions such as the air interface access control, Packet scheduling on the air interface and Packet assembly and reassembly.
a) GGSN
b) PCU
c) SGSN
d) CGF
17. The ______is analogous to the Mobile Switching Center (MSC) /Visitor Location Register (VLR) in the circuit switched domain.
a) GGSN
b) PCU
c) SGSN
d) CGF
18. A given SGSN may serve multiple BSCs. The interface between the SGSN and the BSC is Gb interface, which is a Frame Relay based interface and uses the BSS GPRS protocol (BSSGP).
a) True
b) False
19. ______interface is used by the SGSN to provide location updates to the HLR for GPRS subscribers and to retrieve GPRS related subscription info for any GPRS subscriber that is located in the service area of the SGSN
a) Gb
b) Gr
c) Gc
d) Gd
20. The purpose of ______interface is to enable co-ordination between an MSC/VCR and a SGSN for those subscribers that support both circuit switched services controlled by the MSC/VLR(Such as Voice) and packet data services controlled by the SGSN.
a) Gb
b) Gs
c) Gd
d) Ga
21. The SGSN interfaces with the Short Message Service Center(SMSC) via the ______interface ,which is an SS7- based interface using MAP.
a) Gb
b) Gs
c) Gd
d) Ga
22. The interface between an SGSN and GGSN is known as the ______interface and is an IP-based interface used to carry signaling and user data.
a) Gb
b) Gs
c) Gd
d) Gn
23. The ______interface would be used when the GGSN needs to determine the SGSN currently serving the subscriber, similar to the manner in which the Gateway MSC(GMSC) queries a HLR for routing information for a mobile –terminated voice call.
a) Gc
b) Gs
c) Gd
d) Gn
24. The inter SGSN interface is also termed as the Gn interface and LSO USES GTP and the Primary function of this interface is to enable the tunnelling of the packets from an old SGSN to a new SGSN when a routing area update takes place during an ongoing PDP context.
a) True
b) False
25. SGSN interfaces with a ______for packet transfer to and from given MS.
a) MSC
b) BSC
c) BTS
d) All of the above
26. The ______is to enable support for multiple network protocols and it also enables several packets streams to be multiplexed onto a single logical link between the MS and SGSN.
a) SNDCP
b) LLC
c) LLPDU
d) None of the above
27. At the______, relay function relays LL-PDUs from the Gb interface to the air interface (Um interface)
a) BSS
b) SGSN
c) GGSN
d) LLPDU
28. ______is the protocol used for routing area updates, security functions, (such as authentication), session (that is the PDP context) establishment, modification, and deactivation.
a) GMM/SM
b) SNDCP
c) SGSN
d) TLLI
29. ______is the physical connection between the MS and the network for the duration of the data transmission.
a) Temporary Flow Identity (TFI):
b) Temporary Block Flow (TBF)
c) Temporary Logical Link Identity (TLLI)
d) All of the above
30. Temporary Logical Link Identity (TLLI) is an identifier assigned to a given TBF and is used for distinguishing one TBF from another. A TFI is used in control messages (such as ack) related to a given TBF, so that the entity receiving the control message can correlate the message with the appropriate TBF.
a) True
b) False
31. In ______the network allocates some number of uplink time slots to a user, some number of radio blocks that the MS may transmit, and specifies the TDMA frame when the user may begin transmission. Thus the MS is provided with exclusive access to the time slot for a particular period of time.
a) Dynamic allocation of the uplink
b) Fixed allocation of uplink
c) All of the above
d) None of the above
32. The______must attach to the GPRS network, sot that the GPRS network (SGSN) knows that the MS is available for packet traffic.
a) BSS
b) TFI
c) MS
d) None of the above
33. Upon receipt of the packet Resource Request Message from MS at the BSS, the BSS uses the ______to ack the receipt and the BSS forwards the attach request to an ______
a) PACCH; SGSN
b) SGSN;HLR
c) GGSN;PACCH
d) PACCH;GGSN
34. In Combined ______approach MS instigates an attach to the SGSN , the new SGSN interacts with the VLR to initiate a GSM attach and will go through the BSAAP+ messages; location update request, and location update Accept between the SGSN and the VLR.
a) GPRS/GSM
b) GPRS attach
c) All of the above
d) None of the above
35. The transfer of packet data through the establishment of a Packet data Protocol (PDP) context is effectively the start of a data session
a) True
b) False.
36. The mobile country code (MCC) and the Mobile Network Code (MNC) are part of the International Mobile Subscriber Identity that identifies the subscribers and is available at the SGSN.
a) True
b) False
37. APN operator identifier is used to route packets form a roaming subscriber to a GGSN in the home network in case the APN from the subscriber does not include an APN operator identifier. Based on the APN received the SGSN determines the ______that should be used
a) SGSN
b) GGSN
c) MNC
d) MCC
38. APN operator identifier is used to route packets form a roaming subscriber to a GGSN in the home network in case the APN from the subscriber does not include an APN operator identifier. Based on the APN received the SGSN determines the ______that should be used
a) SGSN
b) GGSN
c) MNC
d) MCC
39. Air Interface Dimensioning estimates the amount of ______that a given cell will be required to handle in the busy hour and this can be done by estimating the number of GPRS users in the cell and estimating the usage requirements of those users .
a) EDGE
b) data traffic(BPS)
c) PDCH
d) BCCH
40. GPRS and GSM the voice traffic follows an ______distribution
which requires that there be more channels in a cell than are used on an
average by the voice traffic.
a) SDCCH
b) Erlang
c) PDCH
d) None of the above
41. The basic goal with ______is to enhance the data throughput capabilities of a GSM/GPRS network.
a) GMSK
b) EDGE
c) EGPRS
d) PDTCH
42. 0.3 GMSK means that the modulator has a band pass filter with a ______bandwidth of 81.25 kHz.
a) 9db
b) 3 db
c) 6db
d) None of the above
43. In EDGE, higher band width efficiency is achieved through the use of ______modulation
a) GMSK
b) 8 PSK
c) GSM
d) PSK
44. With the help of tehe diagram explain the working of the GPRS architecture.
Fig 5-2 shows the GPRS network architecture
The addition new units are
1.Packet Control Unit (PCU)
2.GPRS Support Node (SGSN)
3.Gateway GPRS Support Node (GGSN)
4.Charging Gateway Function (CGF)
45. With he help of the diagram explain briefly how the PDP context is activated.
The transfer of packet data is through the establishment of a Packet data Protocol (PDP) context, which is effectively is a data session
•PDP context is initiated by the MS when a browser is activated and the subscribers home page is is retrieved from the Internet
•The initiation is shown in fig 5-7.
•MS requests for activation of a PDP context and this request includes a number of important information elements listed below
•Network Service Access point Identifier (NSAPI) indicating the type of service IP/X.25
•LLC service Access point Identifier (SAPI) indicating the user data transfer, mobility management signaling, or SMS
•Quality of service (QoS) in terms of acceptable packet loss delay etc