Private:Ahmed Reading Summaries

Will summarize the readings here..

Peer-to-Peer and SVC

Peer-Driven Video Streaming: Multiple Descriptions versus Layering
Layered Coding vs. Multiple Descriptions for Video Streaming over Multiple Paths
Evaluation of the H.264 Scalable Video Coding in Error Prone IP Networks
Overview of the Scalable Video Coding Extension of the H.264/AVC Standard
Enabling Adaptive Video Streaming in P2P Systems

Long Term Evolution (LTE)

Mobile Video Transmission Using Scalable Video Coding
LTE - An Introduction
Optimal Transmission Scheduling for Scalable Wireless Video Broadcast with Rateless Erasure Correction Code
Dynamic Session Control for Scalable Video Coding over IMS
Mobile Broadband: Including WiMAX and LTE
- Chapter-11: Long Term Evolution of 3GPP
3G Evolution HSPA and LTE for Mobile Broadband
- Chapter-11: MBMS: Multimedia Broadcast Multicast Service
The UMTS Long Term Evolution: From Theory to Practice
- Chapter-2: Network Architecture
- Chapter-14: Broadcast Operation

Acronyms

3GPP 3rd Generation Partnership Project
BM-SC Broadcast Multicast Service Centre
CN Core Network
EPC Evolved Packet Core
EPS Evolved Packet System
ICI InterCell Interference
LTE Long Term Evolution
MBMS Multimedia Broadcast Multicast Service
MIMO Multiple Input Multiple Output
OFDMA Orthogonal Frequency Division Multiple Access
SAE System Architecture Evolution
SC-FDMA Single Carrier Frequency Division Multiple Access
TTI Transmission Time Interval
UE User Equipment
UTRAN UMTS Terrestrial Radio Access Network

Long Term Evolution of 3GPP

LTE PHY Layer

Based on OFDMA with cyclic prefix in downlink, and on SC-FDMA with a cyclic prefix in the uplink
Three duplexing modes are supported: full duplex FDD, half duplex FDD, and TDD
Two frame structure types:
- Type-1 shared by both full- and half-duplex FDD
- Type-2 applicable to TDD
Type-1 radio frame has a length of 10 ms and contains 20 slots (slot duration is 0.5 ms)
Two adjacent slots constitute a subframe of length 1 ms
Supported modulation schemes are: QPSK, 16QAM, 64QAM
Broadcast channel only uses QPSK
Maximum information block size = 6144 bits
CRC-24 used for error detection

[Image Placeholder - Type-1 and Type-2 frames]

OFDMA Downlink

Scheduler in eNB (base station) allocates resource blocks (which are the smallest elements of resource allocation) to users for predetermined amount of time
Slots consist of either 6 (for long cyclic prefix) or 7 (for short cyclic prefix) OFDM symbols
Longer cyclic prefixes are desired to address longer fading
Number of available subcarriers changes depending on transmission bandwidth (but subcarrier spacing is fixed)

[Image Placeholder - Downlink resource block and slot structure]

Evolved Multicast Broadcast Multimedia Services (eMBMS)

Is a multimedia service performed either with a single-cell broadcast or multicell mode (aka MBMS Single Frequency Network (MBSFN))
In an MBSFN area, all eNBs are synchronized to perform sumulcast transmission from multiple cells (each cell transmitting identical waveform)
There are three types of cells within an MBSFN area: transmitting/receiving, transmitting only, and reserved
If user is close to a base station, delay of arrival between two cells could be quite large, so the subcarrier spacing is reduced to 7.5 KHz and longer CP is used

LTE MAC Layer

eNB scheduler controls the time/frequency resources for a given time for uplink and downlink
Scheduler dynamically allocates resources to UEs at each Transmission Time Interval (TTI)
Depending on channel conditions, scheduler selects best multiplexing for UE
Downlink LTE considers the following schemes as a scheduler algorithm:
- Frequency Selective Scheduling (FSS)
- Frequency Diverse Scheduling (FDS)
- Proportional Fair Scheduling (PFS)
Link adaptation is performed through adaptive modulation and coding

Mobile Video Transmission Using Scalable Video Coding

MBMS extends existing 3GPP architecture by introducing:
- MBMS Bearer Service delivers IP multicast datagrams to multiple receivers using minimum radio and network resources and provides an efficient and scalable means to distribute multimedia content to mobile phones
- MBMS User Services
  - streaming services - a continuous data flow of audio and/or video is delivered to the user's handset
  - download services - data for the file is delivered in a scheduled transmission timeslot
The p-t-m MBMS Bearer Service does neither allow control, mode adaptation, nor retransmitting lost radio packets (thus, QoS provided for transport of multimedia applications is in general not sufficiently high to support a significant portion of the users for either download or streaming applications)
Consequently, 3GPP included an application layer FEC based on Raptor codes for MBMS
MBMS User Services may be distributed over p-t-p links if decided to be more efficient

MBMS

Introduced for WCDMA (UMTS) in Release 6
Supports multicast/broadcast services in a cellular system
Same content is transmitted to multiple users located in a specific area (MBMS service area) in a unidirectional fashion
The Broadcast Multicast Service Center (BM-SC) node is responsible for authorization and authentication of content provider, charging, and overall data flow through Core Network (CN)
In case of multicast, a request to join the session has to be sent to become member of the corresponding MBMS service group
In contrast to previous releases of Universal Terrestrial Radio Access Network (UTRAN), in MBMS a data stream intended for multiple users is not split until necessary (in UTRAN, one stream per user existed both within CN and RAN)
MBMS services are power limited and maximize the diversity without relying on feedback from users
Two techniques are used to provide diversity:
- Macro-diversity: combining transmission from multiple cells
  - Soft combining: combines the soft bits received from the different radio links prior to (Turbo) coding
  - Selection combining: decoding the signal received from each cell individually, and for each TTI selects one (if any) of the correctly decoded data blocks for further processing by higher layers
- Time-diversity: against fast fading through a long Transmission Time Interval (TTI) and application-level coding
  - because broadcast cannot rely on feedback, MBMS uses application-level forward error-correcting coding, namely Systematic Raptor codes