Zusammenfassung der Ressource
Frage 1
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Tries to satisfy the necessities that appeared when data usage started to grow.
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Only supports packet-switching.
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Belongs to the third generation of mobile networks because it doesn’t achieve IMT-Advanced requirements.
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Belongs to the fourth generation of mobile networks because it does achieve IMT-Advanced requirements.
Frage 2
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Some of the fourth generation requirements are:
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Minimum bit rates of 100 Mbps in the downlink and 50 Mbps in the uplink.
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Support for broadcast and multi-cast.
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Scalable bandwidth from 0 to 20 MHz.
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High VoIP capacity.
Frage 3
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LTE uses different modulations for its links:
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OFDMA is used for the uplink and SC-FDMA for the downlink.
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OFDMA is used for the uplink and WCDMA for the downlink.
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WCDMA is used for the uplink and OFDMA for the downlink.
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OFDMA is used for the downlink and SC-FDMA for the uplink.
Frage 4
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Can be just normal.
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May be normal or extended.
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Lasts 5.2 us the first time and 4.7 us all other times in the normal case, and lasts 16.7 us in the extended case.
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Lasts 5.2 us the first time and 4.7 us all other times in the extended case, and lasts 16.7 us in the normal case.
Frage 5
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Has a duration of 10 ms and is subdivided into ten 1 ms subframes, each of which is split into two 0.5 ms slots.
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Has a duration of 10 ms and is subdivided into five 2 ms subframes, each of which is split into two 0.5 ms slots.
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Has a duration of 1 ms and is subdivided into ten 0.1 ms subframes, each of which is split into four 0.025 ms slots.
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Has a duration of 10 ms and is subdivided into ten 1 ms subframes, each of which is split into four 0.25 ms slots.
Frage 6
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The smallest unit of resource is the Resource Block, which consists of one subcarrier for a duration of one OFDM symbol.
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The smallest unit of resource is the Resource Element, which consists of one subcarrier for a duration of one OFDM symbol.
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Each unit of 12 subcarriers (with a subcarrier spacing of 15 kHz) for a duration of one slot is termed a Resource Element.
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Each unit of 12 subcarriers (with a subcarrier spacing of 15 kHz) for a duration of one slot is termed a Resource Block.
Frage 7
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Some of the downlink’s physical channels and signals are:
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Physical Hybrid ARQ Indicator Channel (PHICH).
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Physical Broadcast Channel (PBCH).
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SRS (Sounding Reference Signal).
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PRACH (Physical Random Access CHannel).
Frage 8
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Is formed by eNodeBs inter-connected with each other by means of interfaces called X2 and to the EPC by means of the S1 interface.
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X2 interfaces are used to avoid data loss during handovers, to perform load balancing and to perform cancel interference.
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Is formed by diverse entities, such as MME, S-GW or P-GW.
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ENodeBs are responsible for managing and allocating radio resources, controlling mobility, positioning, IP headers compression among others.
Frage 9
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Serves as a local mobility anchor for the handover between eNodeBs and between 3GPP (GPRS, UMTS, etc.).
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It is the control node that processes the signaling between the UE and the CN, on which the Non-Access Stratum (NAS) protocols are applied.
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Is responsible for IP address allocation to UEs, and for activities related to quality of service and flow management.
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Defines the rules for charging and policy control.
Frage 10
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LTE-A is considered as belonging to the fourth generation.
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LTE-B provides physical layer improvements and higher energy efficiency.
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The architecture of LTE-B consists of elements such as VLR, AUC, or MSC among others.
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LTE-A makes use of relays to improve coverage.