--- a/src/lte/doc/source/lte-design.rst Sun Dec 11 18:34:53 2011 +0100
+++ b/src/lte/doc/source/lte-design.rst Mon Dec 19 12:33:41 2011 +0100
@@ -417,13 +417,13 @@
-----
+
MAC
-----
++++
The FemtoForum MAC Scheduler Interface
-++++++++++++++++++++++++++++++++++++++
+--------------------------------------
This section describes the ns-3 specific version of the LTE MAC
Scheduler Interface Specification published by the FemtoForum [FFAPI]_.
@@ -503,7 +503,7 @@
Resource Allocation Model
-+++++++++++++++++++++++++
+-------------------------
We now briefly describe how resource allocation is handled in LTE,
@@ -541,7 +541,7 @@
.. _sec-lte-amc:
Adaptive Modulation and Coding
-++++++++++++++++++++++++++++++
+------------------------------
The Adaptive Modulation and Coding (AMC) model that we provide in the
simulator is a modified version of the model described in [Piro2011]_,
@@ -574,14 +574,14 @@
Round Robin (RR) Scheduler
-++++++++++++++++++++++++++
+--------------------------
The Round Robin (RR) scheduler is probably the simplest scheduler found in the literature. It works by dividing the
available resources among the active flows, i.e., those logical channels which have a non-empty RLC queue. If the number of RBGs is greater than the number of active flows, all the flows can be allocated in the same subframe. Otherwise, if the number of active flows is greater than the number of RBGs, not all the flows can be scheduled in a given subframe; then, in the next subframe the allocation will start from the last flow that was not allocated. The MCS to be adopted for each user is done according to the received wideband CQIs.
Proportional Fair (PF) Scheduler
-++++++++++++++++++++++++++++++++
+--------------------------------
The Proportional Fair (PF) scheduler [Sesia2009]_ works by scheduling a user
when its
@@ -649,7 +649,7 @@
Transport Blocks
-+++++++++++++++++++++
+----------------
The implementation of the MAC Transport Blocks (TBs) is simplified with
respect to the 3GPP specifications. In particular, a simulator-specific class (PacketBurst) is used to aggregate
@@ -663,15 +663,15 @@
-------------
+
RLC and PDCP
-------------
+++++++++++++
Overview
-++++++++
+--------
The RLC entity is specified in the 3GPP technical specification
[TS36322]_, and comprises three different types of RLC: Transparent
@@ -697,10 +697,10 @@
Service Interfaces
-++++++++++++++++++
+------------------
PDCP Service Interface
-----------------------
+^^^^^^^^^^^^^^^^^^^^^^
The PDCP service interface is divided into two parts:
@@ -708,7 +708,7 @@
* the ``PdcpSapUser`` part is provided by the upper layer and used by the PDCP layer.
PDCP Service Primitives
-^^^^^^^^^^^^^^^^^^^^^^^
+"""""""""""""""""""""""
The following list specifies which service primitives are provided by the PDCP service interfaces:
@@ -723,7 +723,7 @@
in the receiver peer
RLC Service Interface
----------------------
+^^^^^^^^^^^^^^^^^^^^^
The RLC service interface is divided into two parts:
@@ -733,7 +733,7 @@
Both the UM and the AM RLC entities provide the same RLC service interface to the upper PDCP layer.
RLC Service Primitives
-^^^^^^^^^^^^^^^^^^^^^^
+""""""""""""""""""""""
The following list specifies which service primitives are provided by the RLC service interfaces:
@@ -748,7 +748,7 @@
in the receiver peer
MAC Service Interface
----------------------
+^^^^^^^^^^^^^^^^^^^^^
The MAC service interface is divided into two parts:
@@ -756,7 +756,7 @@
* the ``MacSapUser`` part is provided by the upper RLC layer and used by the MAC layer.
MAC Service Primitives
-^^^^^^^^^^^^^^^^^^^^^^
+""""""""""""""""""""""
The following list specifies which service primitives are provided by the MAC service interfaces:
@@ -781,10 +781,10 @@
Interactions between entities and services
-++++++++++++++++++++++++++++++++++++++++++
+------------------------------------------
Transmit operations in downlink
--------------------------------
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
The following sequence diagram shows the interactions between the
different entities (RRC, PDCP, AM RLC, MAC and MAC scheduler) of the
@@ -837,7 +837,7 @@
PDU to the MAC entity.
Retransmission in downlink
---------------------------
+^^^^^^^^^^^^^^^^^^^^^^^^^^
The sequence diagram of Figure :ref:`fig-lte-rlc-data-retx-dl` shows
the interactions between the different entities (AM RLC, MAC and MAC
@@ -860,7 +860,7 @@
Retransmission Buffer.
Transmit operations in uplink
------------------------------
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
The sequence diagram of Figure :ref:`fig-lte-rlc-data-txon-ul` shows
the interactions between the different entities of the UE (RRC, PDCP,
@@ -881,7 +881,7 @@
channel.
Retransmission in uplink
-------------------------
+^^^^^^^^^^^^^^^^^^^^^^^^
The sequence diagram of Figure :ref:`fig-lte-rlc-data-retx-ul` shows
the interactions between the different entities of the UE (AM RLC and
@@ -898,13 +898,13 @@
AM data transfer
-++++++++++++++++
+----------------
The processing of the data transfer in the AM RLC entity is explained in section 5.1.3 of [TS36322]_.
In this section we describe some details of the implementation of the RLC entity.
Management of buffers in transmit operations
---------------------------------------------
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
The AM RLC entity manages 3 buffers:
@@ -924,7 +924,7 @@
Calculation of the buffer size
-------------------------------
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
The Transmission Buffer contains RLC SDUs. A RLC PDU is one or more SDU segments plus an RLC header.
The size of the RLC header of one RLC PDU depends on the number of SDU segments the PDU contains.
@@ -951,7 +951,7 @@
Concatenation and Segmentation
-------------------------------
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
The AM RLC entity generates and sends exactly one RLC PDU for each transmission opportunity even
if it is smaller than the size reported by the transmission opportunity. So for instance, if a
@@ -964,7 +964,7 @@
It is noted that, according to the 3GPP specs, there is no concatenation for the Retransmission Buffer.
Re-segmentation
----------------
+^^^^^^^^^^^^^^^
The current model of the AM RLC entity does not support the
re-segmentation of the retransmission buffer. Rather, the AM RLC
@@ -974,7 +974,7 @@
Unsupported features
---------------------
+^^^^^^^^^^^^^^^^^^^^
We do not support the following procedures of [TS36322]_ :
@@ -992,7 +992,7 @@
RLC/SM
-++++++++++++++++++
+------
In addition to the full-fledged RLC/UM and RLC/AM implementations,
a simplified RLC model is provided, which is denoted RLC/SM. This RLC model does not accepts
@@ -1029,7 +1029,7 @@
PDCP
-++++
+----
The reference document for the specification of the PDCP entity is
[TS36323]_. With respect to this specification, the PDCP model
@@ -1050,9 +1050,9 @@
----
+
RRC
----
++++
At the time of this writing, the RRC model implemented in the
simulator is not comprehensive of all the funcionalities defined
@@ -1077,27 +1077,27 @@
----
+
PHY
----
++++
Overview
-++++++++
+--------
The physical layer model provided in this LTE simulator is based on
the one described in [Piro2011]_, with the following modifications. The model now includes the
inter cell intereference calculation and the simulation of uplink traffic, including both packet transmission and CQI generation.
CQI feedback
-+++++++++++++
+^^^^^^^^^^^^
The generation of CQI feedback is done accordingly to what specified in [FFAPI]_. In detail, we considered the generation
of periodic wideband CQI (i.e., a single value of channel state that is deemed representative of all RBs
in use) and inband CQIs (i.e., a set of value representing the channel state for each RB).
Interference Model
-++++++++++++++++++
+^^^^^^^^^^^^^^^^^^
The PHY model is based on the well-known Gaussian interference models, according to which the powers of interfering signals (in linear units) are summed up together to determine the overall interference power.
@@ -1114,7 +1114,7 @@
LTE Spectrum Model
-++++++++++++++++++
+^^^^^^^^^^^^^^^^^^
The usage of the radio spectrum by eNBs and UEs in LTE is described in
[TS36.101]_. In the simulator, radio spectrum usage is modeled as follows.