pasapaknga:

missmyhanh:

desiniggs:

iheartfreakinbieber:

musicisplayedforlove:

ithinkyoullbemine:

areienee:

lalalovebianca:

misspurpleaddict:

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colorfulcatastrophe:

a-l:

janamaemae:

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xjamiedc:

juicycandy:

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shelaayjoy:

marlaaa:

sannnnnndy:

(via ariannakhabanh, hiimronjose)

 OMFG OMFG OMFG THIS IS TRUE, MY FRIEND DIED FROM THIS

UGH, i hate when people post shit like this!!

I feel stupid reblogging this BUT I havent had my period for a while and I’m kind of getting scared. So sorry guyths x)

:\ they never stop..ugh.

tangina cge na nga.

TANGENAH. REBLOG KO NA LNG.

Tae to, nanakot! haha.Nothin’ to worry about malayo. Pero, para sure lang tlg

bibingkagirl:

bibingkagirl:

eevverrythinghappensforareason:

elysasakurai:

cookiesandwater:

I LOVE MY MOM.Instant reblog not going to take the chance. 

Death ain’t touching my momma duke!

lmao aw .

 hahah im reploging cause of the gifs

F.U. Not my mom you son of a …

seventh day .

[ make up class ] .

MOBILE TELEPHONY .

HIstory .

•  1947 Bell labs was the first to propose cellular radio telephone network.
• Bell Labs installed the first commercial cellular network in Chicago in the 1970’s
•  Automatic Switching (no gap)
• First mobile phone, Nokia Communicator.

Cellular Networks

• is a radio network distributed over land areas called cells, each served by at least one fixed-location transceiver known as a cell site or base station.
• When joined together these cells provide radio coverage over a wide geographic area.
• This enables a large number of portable transceivers ( mobile phones, pagers, etc,. ) to communicate with each other and with fixed transceivers and telephones anywhere in the network, via base stations, even if some of the transceivers are moving through more than one cell during transmission.

• Cellular networks offer a number of advantages over alternative solutions:

  • increased capacity
  • reduced power use
  • larger coverage area
  • reduced interference from other signals

CSMA/CA - Carrier Signal Multiple Access/Collision Avoidance (Wireless)

TCP/IP - Transmission Control Protocol/ Internet Protocol

Cellular System

• Mobile phones send and receive radio signals with any number of cell site base station fitted with microwave antennas.
• nearest cell sites, 8 to 13 km away. (aprox 5 to 8 miles).
• Handoff or handover process. Two kinds: Hard handover & soft handover
• Cell sites have relatively low-power (often only one or two watts) radio transmitters.

Terrestrial Wireless Network

— On January 14, 2010 TerreStar announced that the Federal Communications Commission had approved the company’s deployment of a terrestrial wireless network using the same S-band frequencies used by TerreStar-1

Cellular Hierarchy*

Radio Spectrum

• refers to the part of the Electronicmagnetic spectrum corresponding to radio frequencies – that is, frequencies lower than around 300 GHz (or, equivalently, wavelengths longer than about 1 mm).
• Different parts of the radio spectrum are used for different radio transmission technologies and applications.

Two techniques for sharing mobile-to-base station radio spectrum

•   TDMA - Time Division Multiple Access
•   FDMA -  Frequency Division Multiple Access

   GSM -  Global System for Mobile Communication

   SDMA- Space Division Multiple Access

Impact in Society

• 90% of the world population has access to mobile phones by 2010.
• 500M active mobile phone accounts in China of 2007

— Law Enforcement.

— Disaster Response.

— Human Health

— Human Behavior

— Environmental Impacts

CELL FUNDAMENTALS*

CELL SPLITTING*

Femtocells

— is a small cellular base station, typically designed for use in a home or small business.

— It connects to the service provider’s network via broadband (such as DSL or cable); current designs typically support 2 to 4 active mobile phones in a residential setting, and 8 to 16 active mobile phones in enterprise settings.

— A femtocell allows service providers to extend service coverage indoors, especially where access would otherwise be limited or unavailable.

Picocells

— is a small cellular basestation typically covering a small area, such as in-building (offices, shopping malls, train stations, etc.), or more recently in-aircraft.

— In cellular networks, picocells are typically used to extend coverage to indoor areas where outdoor signals do not reach well, or to add network capacity in areas with very dense phone usage, such as train stations.

— provides larger coverage than femtocells.

Microcells

— is a cell in a mobile phone network served by a low power cellular base station(tower), covering a limited area such as a mall, a hotel, or a transportation hub

— A microcell is usually larger than a picocell, though the distinction is not always clear. A microcell uses power control to limit the radius of its coverage area

Macrocells

— is a cell in a mobile phone network that provides radio coverage served by a power cellular base station (tower).

— provides larger coverage than microcells.

Megacells

— provides larger coverage than macrocells.

Frequency reuse

•  Radio Spectrum
• 4G System - WiMAX

— 4G stands for the fourth generation of cellular wireless standards. It is a successor to 3G and 2G  families of standards.

• ETSI. ( European Telecommunications Standards Institute )

— is an independent, non-profit, standardization organization in the telecommunications industry (equipment makers and network operators) in Europe, with worldwide projection.

different acronyms .. 

CSMA/CA- Carrier Signal Multiply Access Collision Avoidance

TCP/IP- Transmission Control Protocol, and Internet Protocol

TDMA-Time division multiple access

— is a channel access method for shared medium networks. It allows several users to share the same frequency channel by dividing the signal into different time slots.

FDMA- Frequency Division Multiple Access

— is a channel access method used in multiple-access protocols as a channelization protocol. FDMA gives users an individual allocation of one or several frequency bands, or channels.

 
PDC- Personal Digital Cellular 

— is a 2G mobile telecommunications standard developed and used exclusively in Japan

GSM- Global System for Mobile Communication

— is an international wireless communications standard for railway communication and applications.

SDMA - Space Division Multiple Access

—  is a channel access method based on creating parallel spatial pipes next to higher capacity pipes through spatial multiplexing and/or diversity, by which it is able to offer superior performance in radio multiple access communication systems.

EIA - Electronic Industries Alliance

—is a standards and trade organization composed as an alliance of trade associations for electronics manufacturers in the United States. Those associations in turn govern sectors of EIA standards activity.

TIA - The Telecommunications Industry Association

— is a global trade association headquartered in the United States that represents about 600 telecommunications companies. TIA helps create universal networking and education standards for the telephony, data networking, and convergence industry. TIA has helped develop networking standards that have been used worldwide.

GPRS - General packet radio service

EDGE *

UMTS - Universal Mobile Telecommunication System

— END —

sixth day .

— OSI model ( open system Interconnection model)

— it is a way of sub-dividing communication systems into smaller parts called layers.

— on each layer, an instance provides services to the instances at the layer above requests service from the layer below.

— the seven layers :

application -> presentation -> session -> transport -> network -> data link  -> physical

— physical layer :

the actual physics of the network.

>signaling, cabling, connection.

>this layer is not about protocols.

problems :

>check cabling, terminations, connectors, etc,.

>loopback tests, replace cables, swap adapter cards.

— data link layer :

>is responsible for getting the traffic on the network in communicating using a language that everything on the network can understand.

> data link control (dlc) protocol

>mac (media access control) address on ethernet

>every device has an address to be able to communicate to a network.

— network layer :

>devices communicating that are physically away from each other.

>The routing layer

Switches (layer2)

Routers (layer3)

>internet protocol (IP)

>fragments frames to transverse different network

IP FRAGMENTATION *      MTU*

—Transport layer

>transfer of data between end users

>controls the reliability of a given link

>flow control, segmentation/desegmentation, and error control

>the “post office/truck” layer

-parcel and letters

-variety of package

TCP*   UDP*

— Session layer :

>communicating management between devices

-          start, stop, restart

-          half-duplex, full-duplex

— presentation layer :

>character encoding

>often combined with the application layer

>encrypts and decrypts data

>deals with the syntax and grammatical rule

>file structure

— application layer :

>it provides a user interface

>the laywer we see

>it provides network services such as file transfer, mail service or terminal emulation e.g. FTP, telnet, snmp

>http, ftp, dns, pop3

encapsulation*

— END —

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—APPLICATION LAYER—

• HTTP, HyperText Transfer Protocol

-The Hypertext Transfer Protocol (HTTP) is a networking protocol for distributed, collaborative, hypermedia information systems. HTTP is the foundation of data communication for the World Wide Web.

• APPC, Advanced Program-to-Program Communication

-Advanced Program to Program Communication or APPC is a protocol which computer programs can use to communicate over a network. APPC is at the application layer in the OSI model, it enables communications between programs on different computers, from portables and workstations to midrange and host computers.

• BOOTP, Bootstrap Protocol

-the Bootstrap Protocol, or BOOTP, is a network protocol used by a network client to obtain an IP address from a configuration server. The BOOTP protocol was originally defined in RFC 951

• NNTP, Network News Transfer Protocol

-The Network News Transfer Protocol (NNTP) is an Internet application protocol used for transporting Usenet news articles (netnews) between news servers and for reading and posting articles by end user client applications.

Others are :

·  NTCIP, National Transportation Communications for Intelligent Transportation System Protocol

·  NTP, Network Time Protocol

·  OSCAR, AOL Instant Messenger Protocol

·  PNRP, Peer Name Resolution Protocol

·  POP, POP3, Post Office Protocol(version 3)

·  RDP, Remote Desktop Protocol

·  Rlogin, Remote Login in UNIX Systems

·  RPC, Remote Procedure Call

·  RTMP Real Time Messaging Protocol

·  RTP, Real-time Transport Protocol

·  RTPS, Real Time Publish Subscribe

·  RTSP, Real Time Streaming Protocol

·  SAP, Session Announcement Protocol

·  SDP, Session Description Protocol

·  SIP, Session Initiation Protocol

·  SLP, Service Location Protocol

·  SMB, Server Message Block

·  SMTP, Simple Mail Transfer Protocol

·  SNMP, Simple Network Management Protocol

·  SNTP, Simple Network Time Protocol

—PRESENTATION LAYER—

• AFP, Apple Filing Protocol

-The Apple Filing Protocol (AFP) is a network protocol that offers file services for Mac OS X and original Mac OS.

• ASCII, American Standard Code for Information Interchange
• EBCDIC, Extended Binary Coded Decimal Interchange Code
• ICA, Independent Computing Architecture, the Citrix system core protocol
• LPP, Lightweight Presentation Protocol

• NCP, NetWare Core Protocol

-The NetWare Core Protocol (NCP) is a network protocol used in some products from Novell, Inc. It is usually associated with the NetWare operating system, but parts of it have been implemented on other platforms such as Linux, Windows NT and various flavors of Unix.

• NDR, Network Data Representation
• XDR, eXternal Data Representation

• X.25 PAD, Packet Assembler/Disassembler Protocol

-X.25 is an ITU-T standard protocol suite for packet switched wide area network (WAN) communication. An X.25 WAN consists of packet-switching exchange (PSE) nodes as the networking hardware, and leased lines, Plain old telephone service connections or ISDN connections as physical links. X.25 is a family of protocols that was used especially during the 1980s by telecommunications companies and in financial transaction systems such as automated teller machines.

reference: www.wikipedia.org

—SESSION LAYER—

•  ASP, Appletalk session protocol

• ADSP, Appletalk data stream protocol

-AppleTalk is a propriety suites of protocols developed by Apple Inc. for networking computers.

• H.245, Call Control Protocol for Multimedia Communication

-H.245 is a control channel protocol used with[in] e.g. H.323 and H.324 communication sessions, and involves the line transmission of non-telephone signals. It also offers the possibility to be tunneled within H.225.0 call signaling messages. This eases firewall traversing.

• ISO-SP, OSI Session Layer Protocol (X.225, ISO 8327)
• iSNS, Internet Storage Name Service

-the proposed Internet Storage Name Service (iSNS) protocol allows automated discovery, management and configuration of iSCSI and Fibre Channel devices (using iFCP gateways) on a TCP/IP network.

• L2F, Layer 2 Forwarding Protocol

-Layer 2 Forwarding, is a tunneling protocol developed by Cisco Systems, Inc. to establish virtual private network connections over the Internet. L2F does not provide encryption or confidentiality by itself; It relies on the protocol being tunneled to provide privacy. L2F was specifically designed to tunnel Point-to-Point Protocol (PPP) traffic.

• L2TP, Layer 2 Tunneling Protocol

-Layer 2 Tunneling Protocol (L2TP) is a tunneling protocol used to support virtual private networks (VPNs). It does not provide any encryption or confidentiality by itself; it relies on an encryption protocol that it passes within the tunnel to provide privacy.

reference: www.wikipedia.org