VCSFlagy/n

StreamingFlagy/n

PacketsFlagy/n

Contents of this field are based upon the value in the VCS_Flag field:

This field is only present when the VCS_Flag=y:

VCS_Counter

• Only present when Streaming_Flag=y• Contents based on value in Packet Flag

InfoField

1bit

1bit

1bit

1 Bit 4 Bits5 Bits

8 Bits (optional)

16 Bits (optional)

RemainderOf VCDF

Virtual Channel Data Field

VCS Flag Value Contents

Yes (1) VCS_ID

No (0) Spare bits

Packet Flag Contents

Yes (1) !st Header Pointer

No (0) Number of Valid Octets

Transfer Frame Structures

Notes: 1) A VC is managed to either contain VC Sub-channels or not 2) Streaming refers to Packets that cross frame boundaries or VCA user octets that need not fill the Information area 3)VCS ID is the identifier field for the VC Sub-channel4) VCA SDUs carry user specified Octets5) VCDF SDU is the contents of a frame’s data field6) VCS Counter provides continuity check for VC Sub-channel

Rationale for Specific Field Placement In Frame Structure1. If included, Insert Zone must be included in all frames of a Master Channel. Can not be encrypted because MC

processing precedes Decryption.• Insert Zone should contain a size field to allow MC Insert Zone Service to operate without setup by Service

Management.2. If Flagged the Secondary header must follow the Insert Zone ( could be prior to or after Security Header)3. The Transfer Frame Data Field is place in a position that VC constructer can insert the VCSub-channel (the Data Field)

directly into the frame without effecting the VC channel processes.

Rationale for Specific Field Placement In Frame Header1. The three flags (FEC, Insert Zone and Secondary Header) are included within first byte of header to fill out the byte.

• The order of appearance of the flags could be changed2. VC ID and SCID Use Fields fill a byte. SCID Use Field is place as the second field in the byte so that it appears just

before the SCID Field.3. The SCID and VC Count Size Fields share a two byte grouping. The placement of the VC Count Size Field follows the

SCID so that it appears just before the VC Count Field.4. The VC Count Field can be zero to seven bytes as identified by the contents of the VC Count Size Field.

Rationale for Specific Field Placement In Frame Data Field Header1. The first byte provides the structural information (bits 0 to 3) and VC Sub-Cannel Identification (bits 4 through 7)2. The VCS Counter field is required only when the Field contains a VC sub-channel.3. The next field is required only if streaming data is flagged. This field is either a first header pointer for packets or a

count of valid octets for VCA Data.

Transfer Frame Header Structural Components

• Version ID- is extended to 4bits to accommodate 3 additional frame versions after this one (1100) is codified

• Destination/Source - Identifies the Spacecraft ID as either the source of the data or the intended recipient

• FEC Included -- signals the inclusion of the CRC (y/n)

• Signals the receiving Master Channel process to check Frame’s validity using attached FECF

• Master Channel Insert Zone contained Flag

• Virtual Channel Secondary Header contained Flag

• Frame Length –(N+1) allows for frame to be as large as 65536 octets

• Virtual Channel ID – accommodates 64 Virtual Channels

• Spacecraft ID use Field can be used by a Mission to organize its data without requiring multiple SCIDs

• Spacecraft ID - allows for 8192 names

• VC Count Size – the contents identify the size of the VC count field– (size can be 0 to 7 octets)

• VC Count –VC counter that has a minimum size of 0 octet and a maximum size of 7 octets;• This counter will need to increment when sequence control is specified for this VC• The content of this field can be user defined when sequence control is not specified for this VC• This field can be used by the crypto authentication process eliminating the need of a second counter

PacketsPacket Service

VCA Service

Octets

OCF ServiceVC_OCF_PDU

Virtual Channel (VC) Formulation•Insert Received VCS-PDUs •Add VC Header and increment VC Counter•Compute and Add Security Header and Trailer•Insert OCF•Compute CRC and add FEC

Master Channel (MC) Formulation•Merge Received VC_PDUs •FEC Coding and Randomization•Add Attached Sync Marker

VCDF_PDU

Virtual Channel_PDU

VCA SAPVCA SAP VCDF_Service

VC_PDU

Master Channel_PDU

MC_PDU

Physical Channel (PC) Formulation•Merge Received MC_PDUs •Add Idle as required

Physical Channel Symbol Stream

VCA SAP

MC Insert

VC SH Service

TransferFrame

PrimaryHeader

TransferFrame

SecurityHeader

Transfer Frame Data Field(VCF_SDU)

Transfer

FrameSecurityTrailer

TransferFrame

OperationalControl Field

TransferFrame

Error ControlField

VC Transfer Frame

6-10 Octets 4 Octets VariableVariableVariable VariableMandatory Optional Optional OptionalOptional Optional

VC Data Field

Received from SAPand inserted into frame

Received from OC Service and

Inserted into frameCalculated and

entered into frame

Computed and entered in frame

Generated and entered into frame 11

44

3322 55

Note: The number within the circles identifies the order of inclusion in the frame formation process

Transfer Frame Assembly

MasterChannel

InsertZone

“fixed”

Optional

VirtualChannel

SecondaryHeader

Variable

Optional

PacketsPacket Service VCA Service

Octets

OCF Service

Virtual Channel (VC) Formulation•Add VC Header and increment VC Counter•Insert Received VC-SDUs •Insert OCF•Compute and Add Security Header and Trailer•Compute and add CRC (optional)

Master Channel (MC) Formulation•Merge Received VC_PDUs •FEC Coding and Randomization•Add Attached Sync Marker

VCDF_SDU (VC_Frame Data Field)

Virtual_Channel_Frame

VCDF_Service

VC_Frame

Master_Channel_Frame

MC_Frame

Physical Channel (PC) Formulation•Merge Received MC_PDUs •Add Idle as required

Physical Channel Symbol Stream

VCS SAP

Data Sub-layer

Input Sub-layer

Link_Transmission_Unit

Physical Layer

Sync& Coding Sub-layer

PacketsPacket Service

VCA Service

Octets

VC_OCF_SDU

• Deliver Received verified VC-Frames • Check VC Continuity• Perform Security Process • Extract OCF

• Delimit Frames using Sync Marker• FEC Decoding and Derandomization• Validate Frame using CRC when contained• Separate MC_Frames

VCS_SDU

Virtual_Channel_Frame

VCDF_Service

Master_Channel_Frame

Physical Channel (PC) Reception•Acquire symbols

Physical Channel Symbol Stream

VCS SAP

Data Sub-layer

Output Sub-layer

Link Transmission_Unit (ASM+VC_Frame)

Physical Layer

Sync& Coding Sub-layer

Transmitting (sending) Side Receiving Side

VC Service

MCF ServiceMC_Frame

VC_Frame

Separate VC_Frames

Separate VC_Frames

Separate GVCS_Frames Select VCF_SDU

Merge VC Frames

Merge MC Frames

Form VCF_SDUForm VCF_SDU VCA SAP

VCA SAPExtract Octets Extract Packets

VC SH Service

MC Insert

Packet SAP VC_OCFService

Data Unit

VCA_SDUs

VCF_SDUsOCF_SDUs

Virtual Channel

Processing

Virtual Channel Creation

Virtual Channel Data Unit (VCDU)

Master Channel Process (Virtual Channel Multiplexing)

Master Channel Data Unit (MCDU)

All Channel Multiplexing

Physical Channel

Coding and Sync Sub-Layer

Packets

PacketProcessingFunction

VCAProcessingFunction

VirtualChannel

Processing

VirtualChannel

Processing

Master ChannelProcess

VCA-SAP

OptionalProcess

Multiplexer

ReplicatedProcesses

Process

Legend

Security Process

CRC Creation

OCF

-SAP

Note: -Packet SAP can support multiple users-VCA SAP can only support a single user

VCDF-SAP

VCDF_SDUs

VCF-SDU = VC Data Field

VCA_SDUs

VCDF_SDUs VCDF_SDUs

Virtual Channel

Processing

Virtual Channel SDU Extraction

Virtual ChannelData Unit (VCDU)

Master Channel Process (Virtual Channel Multiplexing)

Master Channel Data Unit (MCDU)

All Channel Multiplexing

Physical Channel

Coding and Sync Sub-Layer

Packets

PacketProcessingFunction

VCAProcessingFunction

VirtualChannel

Processing

VirtualChannel

Processing

Master ChannelProcess

OptionalProcess

Multiplexer

ReplicatedProcesses

Process

Legend

Security Process

CRC Validation

Packet SAP VCA-SAP

Note: -Security Process may output a report-CRC Validation will output a report to OCF

VCDF-SDUs

VCDF-SAP

VC-SDUs

VC-SAPCOP-1Service

OCF_SDUs

OCF-SAPCRC Report

Managed ParametersMaster Channel---

• FEC Code, • Inter-frame Idle Allowed/not allowed? • Fixed/variable frame length?• VC priorities• Max Frame Size allowed • ASM, • Fill type (frame or bits)

VC --- • Count size• Sequence controlled y/n? • Sequence count indexing required• OCF y/n• Security header & trailer sizes• Security SA (use VC Count?)• VCS/packets/VCA (signaled in frame)• VCS --- list allowed data types • Streaming data (Packets not required to fit within a single frame)

VCS ---• Packets/VCA (signaled in frame)• Size of Field

Short Uplink Code Performance

12

LDPCRate ½ Block size 16 384 bitsRate ½ Block size 1024 1/2, 1024 LDPC with BCH TEDLDPC Rate 4/5 Block size 16384

GSFC-LDPC (8176,7156)

BCH SEC TED

Overall Coding Performance (provided by JPL Coding Group)

TransferFrame

PrimaryHeader

TransferFrame

SecurityHeader

Transfer Frame Data Field

(VCDF_PDU)

TransferFrame

SecurityTrailer

TransferFrame

OperationalControl Field

TransferFrame

Error ControlField

Transfer Frame

6-11 Octets 4 Octets VariableVariableVariable VariableMandatory Optional Optional OptionalOptional Optional

MasterChannel

Insert Zone

Variable

Optional

VirtualChannel

SecondaryHeader

Variable

Optional

VersionID

Destinationor

SourceID

SpacecraftID

Transfer Frame Header

4 bits 1 Bit1 bit 13 bits

VCCount

size

VCCount

6 Bits

Virtual Channel

ID

0-56 Bits3 Bits2 Bits

FECIncluded

Flag

Frame Length

16 Bits

SCIDUseField

InsertZoneFlag

SecondaryHeader

Flag

1 Bit1 Bit

VCSFlagy/n

StreamingFlagy/n

PacketsFlagy/n

Contents of this field are based upon the value in the VCS_Flag field:

This field is only present when the VCS_Flag=y:

VCS_Counter

• Only present when Streaming_Flag=y• Contents based on value in Packet Flag

InfoField

1bit

1bit

1bit

1 Bit 4 Bits5 Bits

8 Bits (optional)

16 Bits (optional)

RemainderOf VCDF

VCS Flag Value Contents

Yes (1) VCS_ID

No (0) Spare bits

Packet Flag Contents

Yes (1) !st Header Pointer

No (0) Number of Valid Octets

Virtual Channel Data Field