showing list of updates available in ubuntu using apt

To see the list of updates available in Ubuntu using apt , use the below command in console

apt-get --just-print upgrade

Wi-Fi (IEEE 802.11) Abbreviations and Acronyms

Based on IEEE 802.11-2012 document

3GPP	3rd Generation Partnership Project
802.x	LAN IEEE 802-based local area networks such as IEEE 802.3 and IEEE 802.11
AA	Authenticator address
AAA	authentication, authorization, and accounting
AAD	additional authentication data
AC	access category
ACI	access category index
ACK	acknowledgment
ACM	admission control mandatory
ACU	admission control unit
ADDBA	add Block Acknowledgment
ADDTS	add traffic stream
AES	advanced encryption standard
AES-128-CMAC	advanced encryption standard (with 128-bit key) cipher-based message authentication code
AFC	Automatic Frequency Control
AGC	Automatic Gain Control
AID	association identifier
AIFS	arbitration interframe space
AIFSN	arbitration interframe space number
AKM	authentication and key management
AKMP	Authentication and Key Management Protocol
AMPE	authenticated mesh peering exchange
A-MPDU	aggregate MAC protocol data unit
A-MSDU	aggregate MAC service data unit
ANonce	Authenticator nonce
ANPI	average noise power indicator
ANQP	Access Network Query Protocol
AP	access point
APSD	automatic power save delivery
ARP	Address Resolution Protocol
AS	Authentication Server
ASEL	antenna selection
ASN.1	Abstract Syntax Notation One
ASRA	additional step required for access
ATIM	announcement traffic indication message
BA	Block Acknowledgment
BAR	Block Acknowledgment request
BCC	binary convolutional code
BIP	Broadcast/Multicast Integrity Protocol
BPSK	binary phase shift keying
BSA	basic service area
BSS	basic service set
BSSID	basic service set identifier
BT	bit time
BU	bufferable unit
CAP	controlled access phase
CBC	cipher-block chaining
CBP	contention-based protocol
CBC-MAC	cipher-block chaining message authentication code
CCA	clear channel assessment
CCK	complementary code keying
CCM	CTR with CBC-MAC
CCMP	CTR with CBC-MAC Protocol
CF	contention-free
CFP	contention-free period
C-MPDU	coded MPDU
CP	contention period
C-PSDU	coded PSDU
CRC	cyclic redundancy code
CS	carrier sense
CSD	cyclic shift diversity
CSI	channel state information
CSMA/CA	carrier sense multiple access with collision avoidance
CTR	counter mode
CTS	clear to send
CTS1	clear to send 1
CTS2	clear to send 2
CW	contention window
DA	destination address
DBPSK	differential binary phase shift keying
DCF	distributed coordination function
DCLA	dc level adjustment
DELBA	delete Block Acknowledgment
DELTS	delete traffic stream
DFS	dynamic frequency selection
DFT	discrete Fourier transform
DIFS	distributed (coordination function) interframe space
DLL	data link layer
DLS	direct-link setup
DLTF	Data Long Training field
DMS	directed multicast service
DMSID	directed multicast service identifier
DN	destination network
DO	DFS owner
Dp	desensitization
DQPSK	differential quadrature phase shift keying
DR	data rate
DS	distribution system
DSCP	differentiated services code point
DSE	dynamic station enablement
DSM	distribution system medium
DSS	distribution system service
DSSDU	distribution system service data unit
DSSS	direct sequence spread spectrum
DSSS-OFDM	Direct sequence spread spectrum orthogonal frequency division multiplexing
DST	daylight saving time
DTIM	delivery traffic indication map
EAP	Extensible Authentication Protocol (IETF RFC 3748-2004 [B38])
EAPOL	Extensible Authentication Protocol over LANs (IEEE Std 802.1X-2004)
EAS	emergency alert system
EBR	expedited bandwidth request
ECS	extended channel switching
ED	energy detection
EDCA	enhanced distributed channel access
EDCAF	enhanced distributed channel access function
EDT	eastern daylight time
EHCC	extended hyperbolic congruence code
EIFS	extended interframe space
EIRP	equivalent isotropically radiated power
ELTF	Extension Long Training field
EOSP	end of service period
ERP	extended rate PHY
ERP-CCK	extended rate PHY using CCK modulation
ERP-DSSS	extended rate PHY using DSSS modulation
ERP-DSSS/CCK	extended rate PHY using DSSS or CCK modulation
ERP-OFDM	extended rate PHY using OFDM modulation
ERP-PBCC	extended rate PHY using extended rate PBCC modulation
ESA	extended service area
ESR	emergency services reachable
ESS	extended service set
EST	eastern standard time
EVM	error vector magnitude
FC	frame control
FCS	frame check sequence
FEC	forward error correction
FER	frame error ratio
FFT	Fast Fourier Transform
FH	frequency hopping
FHSS	frequency-hopping spread spectrum
FIFO	first in first out
FMS	flexible multicast service
FMSID	flexible multicast stream identifier
FOV	field of view
FSM	finite state machine
FT	fast BSS transition
FTAA	fast BSS transition authentication algorithm
FTE	fast BSS transition element
FTO	fast BSS transition originator
GANN	gate announcement
GAS	generic advertisement service
GFSK	Gaussian frequency shift key or keying
GI	guard interval
GMK	group master key
GNonce	group nonce
GPRS	general packet radio service
GPS	Global Positioning System
GTK	group temporal key
GTKSA	group temporal key security association
HC	hybrid coordinator
HCC	hyperbolic congruence code
HCCA	HCF controlled channel access
HCF	hybrid coordination function
HEC	header error check
HEMM	HCCA, EDCA mixed mode
HESSID	homogenous extended service set identifier
HIPERLAN	high-performance radio local area network
HPA	high power amplifier
HR/DSSS	High Rate direct sequence spread spectrum using the long preamble and header
HR/DSSS/PBCC	High Rate direct sequence spread spectrum using the optional packet binary convolutional coding mode and the long preamble and header
HR/DSSS/PBCC/short	High Rate direct sequence spread spectrum using the optional packet binary convolutional coding mode and the optional short preamble and header
HR/DSSS/short	High Rate direct sequence spread spectrum using the optional short preamble and header mode
HT	high throughput
HTC	high throughput control
HT-GF-STF	High-Throughput Greenfield Short Training field
HT-SIG	High-Throughput SIGNAL field
HT-STF	High-Throughput Short Training field
HWMP	hybrid wireless mesh protocol
HWMP SN	hybrid wireless mesh protocol sequence number
IBSS	independent basic service set
ICMP	Internet Control Message Protocol
ICV	integrity check value
IDFT	inverse discrete Fourier transform
IFFT	inverse Fast Fourier Transform
IFS	interframe space
IGTK	integrity group temporal key
IGTKSA	integrity group temporal key security association
IMp	intermodulation protection
INonce	initiator nonce
IPI	idle power indicator
IPN	IGTK packet number
I/Q	in phase and quadrature
IR	infrared
IrDA	infrared data association
ISM	industrial, scientific, and medical
IUT	implementation under test
IV	initialization vector
KCK	EAPOL-Key confirmation key
KDE	key data encapsulation
KDF	key derivation function
KEK	EAPOL-Key encryption key
LAN	local area network
LCI	location configuration information
LDPC	low-density parity check
LED	light-emitting diode
LFSR	linear feedback shift register
LLC	logical link control
L-LTF	Non-HT Long Training field
LME	layer management entity
LNA	low noise amplifier
LRC	long retry count
LSB	least significant bit
L-SIG	Non-HT SIGNAL field
L-STF	Non-HT Short Training field
LTF	Long Training field
MAC	medium access control
MAC_I	initiator mac address
MAC_P	peer mac address
MAF	MCCA access fraction
MBCA	mesh beacon collision avoidance
MBSS	mesh basic service set
MCCA	MCF controlled channel access
MCCAOP	MCF controlled channel access opportunity
MCF	mesh coordination function
MCS	modulation and coding scheme
MDE	Mobility Domain element
MDID	mobility domain identifier
MFB	MCS feedback
MFPC	management frame protection capable
MFPR	management frame protection required
MGTK	mesh group temporal key
MIB	management information base
MIC	message integrity code
MIH	media-independent handover
MIMO	multiple input, multiple output
MLME	MAC sublayer management entity
MLPP	multi-level precedence and preemption
MME	Management MIC element
MMPDU	MAC management protocol data unit
MPDU	MAC protocol data unit
MPM	mesh peering management
MPSP	mesh peer service period
MRQ	MCS request
MSB	most significant bit
MSDU	MAC service data unit
MSGCF	MAC state generic convergence function
MSK	master session key
MTK	mesh temporal key
MUI	message unique identifier
N/A	not applicable
NAI	network access identifier
NAS	network access server
NAV	network allocation vector
NDP	null data packet
NonERP	nonextended rate PHY
NTP	Network Time Protocol (IETF RFC 1305-1992 [B25])
OBSS	overlapping basic service set
OCB	outside the context of a BSS
OFDM	orthogonal frequency division multiplexing
OI	organization identifier
OSI	Open Systems Interconnection (ISO/IEC 7498-1:1994)
OUI	organizationally unique identifier
PAE	port access entity (IEEE Std 802.1X-2004)
PBAC	protected block ack agreement capable
PBCC	packet binary convolutional code
PC	point coordinator
PCF	point coordination function
PCO	phased coexistence operation
PDU	protocol data unit
PER	packet error ratio
PERR	path error
PHB	per-hop behavior
PHY	physical layer
PHYCS	PHY carrier sense
PHYED	PHY energy detection
PICS	protocol implementation conformance statement
PIFS	point (coordination function) interframe space
PLCP	physical layer convergence procedure
PLME	physical layer management entity
PLW	PSDU length word
PMD	physical medium dependent
PMK	pairwise master key
PMK-R0	pairwise master key, first level
PMK-R1	pairwise master key, second level
PMKID	pairwise master key identifier
PMKSA	pairwise master key security association
PN	packet number
PN	pseudonoise (code sequence)
PNonce	peer nonce
PP A-MSDU	payload protected aggregate MAC service data unit
PPDU	PLCP protocol data unit
PPM	pulse position modulation
PREP	path reply
PREQ	path request
PRF	pseudorandom function
PRNG	pseudorandom number generator
PS	power save (mode)
PSAP	public safety answering point
PSDU	PLCP service data unit
PSF	PLCP Signaling field
PSK	preshared key
PSMP	power save multi-poll
PSMP-DTT	power save multi-poll downlink transmission time
PSMP-UTT	power save multi-poll uplink transmission time
PTI	peer traffic indication
PTK	pairwise transient key
PTKSA	pairwise transient key security association
PXU	proxy update
PXUC	proxy update confirmation
QAM	quadrature amplitude modulation
QBPSK	quadrature binary phase shift keying
QLRC	QoS long retry counte
QoS	quality of service
QPSK	quadrature phase shift keying
QSRC	QoS short retry counter
R0KH	PMK-R0 key holder in the Authenticator
R0KH-ID	PMK-R0 key holder identifier in the Authenticator
R1KH	PMK-R1 key holder in the Authenticator
R1KH-ID	PMK-R1 key holder identifier in the Authenticator
RA	receiver address or receiving station address
RADIUS	remote authentication dial-in user service (IETF RFC 2865-2000 [B31])
RANN	root announcement
RAV	resource allocation vector
RCPI	received channel power indicator
RD	reverse direction
RDE	RIC Data element
RDG	reverse direction grant
RF	radio frequency
RFC	request for comments
RIC	resource information container
RIFS	reduced interframe space
RLAN	radio local area network
RPI	receive power indicator
RRB	remote request broker
RSC	receive sequence counter
RSN	robust security network
RSNA	robust security network association
RSNE	Robust Security Network element
RSNI	received signal to noise indicator
RSPI	receiver service period initiated
RSSI	receive signal strength indicator
RTS	request to send
RX	receive or receiver
RXASSI	receive antenna selection sounding indication
RXASSR	receive antenna selection sounding request
S0KH	PMK-R0 key holder in the Supplicant
S0KH-ID	PMK-R0 key holder identifier in the Supplicant
S1KH	PMK-R1 key holder in the Supplicant
S1KH-ID	PMK-R1 key holder identifier in the Supplicant
SA	source address
SAE	simultaneous authentication of equals
SAP	service access point
S-APSD	scheduled automatic power save delivery
SA Query	Security Association Query
SDL	specification and description language
SDU	service data unit
SFD	start frame delimiter
SKCK	STSL key confirmation key
SKEK	STSL key encryption key
SI	service interval
SIFS	short interframe space
SLRC	station long retry count
SM	spatial multiplexing
SME	station management entity
SMK	STSL master key
SMKSA	STSL master key security association
SMT	station management
SNAP	Sub-Network Access Protocol
SNonce	Supplicant nonce
SNR	signal-to-noise ratio
SP	service period
SPA	Supplicant address
SPP A-MSDU	signaling and payload protected aggregate MAC service data unit
SQ	signal quality (PN code correlation strength)
SRC	short retry count
SS	station service
SSID	service set identifier
SSP	subscription service provider
SSPN	subscription service provider network
SSRC	station short retry count
STA	station
STBC	space-time block coding
STK	STSL transient key
STKSA	STSL transient key security association
STSL	station-to-station link
STT	selective translation table
SYNC	synchronization
TA	transmitter address or transmitting station address
TAI	Temps Atomique International (International Atomic Time)
TBTT	target beacon transmission time
TC	traffic category
TCLAS	traffic classification
TDLS	tunneled direct-link setup
TDLS peer PSM	tunneled direct-link setup peer power save mode
TFS	traffic filtering service
TID	traffic identifier
TIE	Timeout Interval element
TIM	traffic indication map
TK	temporal key
TKIP	Temporal Key Integrity Protocol
TMPTT	target measurement pilot transmission time
TOA	time of arrival
TOD	time of departure
TPC	transmit power control
TPK	TDLS Peer Key
TPKSA	TDLS Peer Key Security Association
TPU	TDLS Peer U-APSD
TS	traffic stream
TSC	TKIP sequence counter
TSF	timing synchronization function
TSID	traffic stream identifier
TSN	transition security network
TSPEC	traffic specification
TTAK	TKIP-mixed transmit address and key
TTL	time to live
TTTT	target TIM transmission time
TU	time unit
TX	transmit or transmitter
TXASSI	transmit antenna selection sounding indication
TXASSR	transmit antenna selection sounding request
TXE	transmit enable
TXOP	transmission opportunity
U-APSD	unscheduled automatic power save delivery
UCT	unconditional transition
UESA	unauthenticated emergency service accessible
ULS	Universal Licensing System
U-NII	unlicensed national information infrastructure
UP	user priority
URI	uniform resource identifier
URL	universal resource locator
URN	Uniform Resource Name
UTC	Coordinated Universal Time
VLAN	virtual local area network
VoIP	voice over Internet Protocol (IP)
WLAN	wireless local area network
WDS	wireless distribution system
WEP	wired equivalent privacy
WM	wireless medium
WNM	wireless network management

MySQL max connection status for optimisations

you can use the below query to check the max connection statistics

select version();show variables like "%max_connections%";show global status
         like "%Max_used%";show status like "%thread%";


 Max_used_connections : The maximum number of connections that have been in use simultaneously since the server started.
max_connections : The maximum permitted number of simultaneous client connections.