Middleware and Application pp Software

Hsiao-Lung H i L Chan Ch Dept Electrical Engineering Chang Gung University Taiwan

Middleware within the embedded systems y model 

Reasons to be separate from application software  

Reusability with other applications Decrease development p costs or time byy purchasing p g it from a third party vendor Application Software Layer Application Software Layer System Software Layer Middleware D i Drivers Device D i

Hardware Layer

System Software Layer Middleware Operating System Device Drivers Hardware Layer

2

Networking g middleware example p OSI (Open System Interconnection) Model

Application Layer Presentation Layer

Application Software Layer

Session Layer

Transport Layer

Networking Middleware

Network Layer D t -Link DataData Li k Layer L

Physical Layer

System Software Layer

Hardware Layer

3

OSI model data flow diagram g

Layer 7

Application Layer

Application Layer

Presentation Layer

Presentation Layer

Layer 7

Header 1 Session Layer

Session Layer

Transport Layer

Transport Layer

Network L Layer

Network L Layer

Data Link Layer

Data Link Layer

Physical Layer

Physical Layer

Header 2 Header 3

Layer 1

Transmission media

Data

Header 4

Data

Header 5

Data Data

Data

Data

Application

Data

Presentation Session Transport Network Data Link Physical

Layer 1

4

OSI model layer y 1: Physical y layer y Define the networking hardware

Device 1

Data Link Layer

10011101 101110

Layer 2

Device 2

Layer 1

Physical Layer

Data Link Layer

Transmission Medium

Layer 2

01110101 111001



Physical Layer

Layer 1

5

OSI model layer y 2: Data-link layer y Format bits into data-link frame,, containing g data,, media access control (MAC) address, etc. Layer 3

Dattagra m

Network Layer

Data Link Layer [data] Data-link Headers Stripped Data-link Frame

Data-Link Headers Appended to Data Field

Layer 2

110110101101110111011101110001100111000001100101000111

[Start of frame] [source addr][dest addr][admin][data] [ error chk][end of frame]

1 111011100



Physical Layer

Layer 1 6

OSI model layer y 3: Network layer y  

Manage datagram traffic Add IP (internet protocol) address Layer 4

Pa acket

Transport Layer

Network Layer

[data] Network Header Appended to Data Field

Network Headers Stripped

11011011001101110001100001101101110111011101110001100111000001100101000111

[IP Version] [header len][data type][data len][frag info] [# hops][upper layer][checksum][source IP][dest IP][data]

Datagram

Network Datagram

Layer 3

Data-link Layer

Layer 2

7

OSI model layer y 4: Transport p layer y 



Point-to-point p communication: establish and dissolve communication between two specific devices TCP (Transmission Control Protocol): Sent an acknowledge when receiving packet Layer 5

Message/Pscket

Session Layer

Transport Layer

[data] Transport Headers Stripped

Layer 4

11011011001101110001100001101101110111011101110001100111000001100101000111 [Src Port][Dest Port][Seq #][Ack #][H Len][Res][Uflag][Pflag][Rflag][Sflag][Fflag][WinSz][Chksum][UP[O] [Data]

Pac cket

TCP Packet

Transport Header Appended to Data Field

Network Layer

Layer 3

8

OSI model layer y 5: Session layer y Connection of two network applications Layer 6

Message

Presentation Layer

Session Layer [data]

Layer 5

L2CAP Packet

Session Header Appended to Data Field 1101101100110111000110000110 [Length][Destination Channel ID][Data]

Packet P

Session Headers Stripped

Message/ M



Transport Layer

Layer 4

9

OSI model layer y 6: Presentation layer y Translate data into formats,, e.g. g data compression/decompression, p p , data encryption/decryption, and data protocol/character conversions Layer 7

M Message

Application Layer

Presentation Layer Message conversion Bluetooth Message

[data] Presentation Header Appended to Data Field

Layer 6

1101101100110111000110000110 [Length][Destination Channel ID][Data] M Message



Session Layer

Layer 5

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OSI model layer y 7: Application pp layer y 

Network applications by end end-users users or protocols Application Software Layer MIME POP3

SMTP IMAP4

Finger

FTP

Telnet HTTP

NCP Bootp

APPC SNMP

BT--SDP BT RLOGIN

NFS …

Presentation Layer Session Layer

System y Software Layer y Transport Layer Network Layer Data-link Layer

Hardware Layer Physical Layer 11

TCP/IP, OSI model

TCP/IP Model

OSI Model

Application Layer Application Layer

Presentation Layer

Application Software Layer

Session Layer

Transport Layer Internet Layer

Transport p Layer y

System Software Layer

Network Layer Data--Link Layer Data

Network Access Layer Physical Layer

Hardware Layer

12

Bluetooth, OSI model

Bluetooth Model

OSI Model Application Layer

Application Protocol Group

Application Software Layer Presentation Layer

WAP Session Layer

Middleware Protocol Group TCP/IP

Transport Layer

System y Software Layer y

Network Layer Data--Link Layer Data T Transport t Protocol P t l Group G

Physical Layer

Hardware Layer

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References 

T. Noergaard, Embedded Systems Architecture, Elsevier 2005.

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