Wireless Future - Telenor

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Figure 5 A Bluetooth radio module is fairly small 68 real-time traffic like voice do not contain a CRC field, since retransmission is not appropriate. A robust voice coding scheme is used which can tolerate many errors. This Continuous Variable Slope Delta modulation scheme follows the speech wave form by sampling the wave form and only transferring the difference between consecutive samples. Both data and voice packet may include coding bits for improved robustness. To support both asynchronous traffic like file transfer or web browsing, and synchronous traffic like voice, two types of links with their corresponding packets have been defined. The asynchronous-connection-less (ACL) link is a pointto-multipoint link between the master and the slaves. ACL packets can be sent on any time slot. The slave address (AM_ADDR) is used to deliver the packet to the proper slave. The synchronous-connection-oriented (SCO) link is a point-to-point link between a master and a single slave (though the master can support several SCO links to several slaves). On the SCO link, SCO packets are transmitted at a fixed interval. Time slots are reserved at a fixed interval to provide quality of service for the real-time traffic. To reduce power consumption in low-rate applications, several low-power modes are defined. In the sniff mode, the communication between master and slave only occurs during one TX and RX slot every N slots in which N is the sniff interval. In this case, the slave only has to scan (read sniff) the channel every N slots. In the hold mode, the entire communication between master and slave is suspended for a specified hold window. After the hold window expires, the slave wakes up again and communication can proceed. Finally, in the park mode, the master broadcasts a low-duty cycle beacon signal to which parked slaves are locked. The slave resides in an inactive state but is synchronised to the master. The beacon signal only contains broadcast information to all parked slaves, but can be used to move a parked slave from the inactive park state to the active state where direct communications between master and slave can be achieved. For further details regarding the baseband functionality, see [3]. 2.4 LMP In general, the link manager (LM) is responsible for establishing and supervising the connections and logical links. For initial connection establishment (page and scan routines), only the baseband is involved. This keeps power consumption down in the standby mode. Once the master and slave are synchronized and indeed an FH channel has been established, the link manager protocols are activated. First, authentication procedures are carried out to prevent unauthorized usage of the connected devices. The link manager protocol also plays a role in the key distribution and encryption routine, see also section 3.3. After initial setup and authentication, the LMP takes care of the setup of SCO and/or ACL connections depending on the applications. During the connection, the LMP is involved in link supervision (i.e. selection of specific packets depending on the link quality and the required quality of service), but also takes care of lowpower modes like hold, sniff and park. The link manager in the master is responsible for scheduling the traffic flows to and from the different slaves. Finally, the LMP is used to configure any (optional) parameters in the Bluetooth transceivers both at the start and during the connection. 2.5 L2CAP The Logical Link Control and Adaptation Protocol (L2CAP) takes care of the multiplexing of different services, the segmentation and reassembly of (datagram) packets, for example IP packets, and handles quality of service issues. The L2CAP forms an interface layer between Bluetooth-independent higher-layer protocols, and the Bluetooth-specific LMP layer. During segmentation, the higher-layer traffic is mapped onto baseband packets which are scheduled for transmission by the link manager. Received baseband packets are re-assembled by the L2CAP and relayed to the higher layers. 2.6 HCI In many cases the Bluetooth functionality of the lower layers of the specification will be implemented into a module that can be fitted onto many different kinds of equipment. The Host Control Interface (HCI) forms the interface to the host (e.g. a PC or a cell phone). It provides higher layers with means for accessing some of Telektronikk 1.2001
the hardware status and control registers of the baseband controller and link manager of both the local and the remote Bluetooth devices. To accomplish this, an HCI driver residing in the host communicates over a physical bus (e.g. USB or PC card) with the HCI firmware residing in the local Bluetooth module (see Figure 5). The HCI commands can be classified into three types. Link Control commands are used to directly control the links to other Bluetooth devices. For instance, these messages instruct the LM to establish contact with other devices or perform inquiries. It can also be used to require the other device to authenticate its identity. Link Policy commands affect the behaviour of the local and the remote LM. These commands determine the way piconets and scatternets are established and maintained (e.g. using the sniff and hold modes). Finally, the Host Controller and Baseband commands provide the host access to some registers of the local Bluetooth device. Examples of this are key maintenance, flushing the transmit buffers, and setting various timer values. The execution time of HCI commands are not defined, and it also varies between different commands. Therefore, the host controller sends specific Command Complete events back to the host upon completion of an HCI command. 2.7 Profiles Interoperability is the key issue for Bluetooth. The profiles serve to define a selection of messages and procedures from the Bluetooth SIG specifications and gives an unambiguous description of the air interface for the specified service(s) and use case(s). Thus, devices conforming to a specific profile are able to work together regardless of manufacturer. The conformity to a profile is verified in the certification procedure that each vendor must pass before the Bluetooth brand name can be used for the product. So far, 13 different profiles have been defined. The most important is the Generic Access Profile (GAP) that serves as the foundation for all other profiles. The GAP introduces definitions, recommendations and common requirements related to modes and access procedures that are to be used by the other profiles. It defines how Bluetooth devices in different baseband states (i.e. in idle modes or in connection modes) are to behave so that communication links and channels can be set up and maintained. It also defines procedures related to the use of different security levels and makes multi-profile operations possible. Furthermore, the common format requirements for parameters that are accessible on the user interface level are defined in this profile. Telektronikk 1.2001 The Service Discovery Access Profile (SDAP) relates to how an application on one Bluetooth device can find out and locate a particular service that runs on or through a Bluetooth enabled device in the neighbourhood. There are also profiles defined for Cordless Telephony, Intercom (phone-to-phone), Headset, Dial-up Networking, LAN Access (via PPP), Fax, Serial Port, Generic Object Exchange, Object Push, File Transfer, and Synchronisation. 3 User Scenarios There seems to be an endless amount of usage scenarios for which Bluetooth can serve as an enabling technology. A few of these are described below. 3.1 The Personal Area Network When people communicate directly, the distance between them is fairly small. To some extent, Bluetooth communication can be said to mimic this behaviour since for the most common radio devices the range is limited to approximately 10 m; only devices within this distance can be reached. The relatively small physical size of any network that can be formed, justifies the common notion of it as a Personal Area Network (PAN). The PAN can be viewed as a sphere or “information bubble” around the user. Bluetooth devices within this bubble can be reached, others cannot be contacted. The usefulness of a PAN can easily be illustrated with some examples. It should be noted that the trivial point-to-point connection in some sense also constitutes a PAN, as is described in some of the examples below. • Three-in-one phone: At home this phone will connect via a Bluetooth link to an access point connected to the fixed line network. Alternatively, the phone may connect directly to some other Bluetooth phone using an intercom mode. When the user leaves home, the phone works as a conventional cellular phone (GSM or UMTS). • Universal remote control: Your personal digital assistant (PDA) or cell phone may serve as a remote control not only in your home for residential audio/video equipment, but also as a programmable key to use for locks in your house and for your car. Moreover, it can be programmed for obtaining temporary access to office buildings and hotels you are visiting. • Cordless desktop computer: Almost all wires connected to the back of a desktop computer can be replaced by Bluetooth links: keyboard, mouse, modem, microphone, webcam, speakers, et cetera. 69
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Telektronikk Volume 97 No. 1 - 2001
Page 4 and 5:
Per Hjalmar Lehne (42) obtained his
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Stein Svaet (41) is Senior Research
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Pbit/day 6 150 125 100 75 50 25 0 F
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8 Video communication as a utility
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10 The idea of reconfigurable mobil
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12 Switched lobe Dynamically phased
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Figure 10 The All IP vision Figure
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16 The IP world has some problems t
Page 20 and 21: 18 Abbreviations and acronyms less
Page 22 and 23: Jorge Pereira (40) obtained his Eng
Page 24 and 25: (Millions) Figure 1 Exponential gro
Page 26 and 27: 24 Defining Generation based upon D
Page 28 and 29: Multi-mode Terminal by Software Rad
Page 30 and 31: distribution layer possible return
Page 32 and 33: 30 A Co-Ordinated Approach to 4G As
Page 34 and 35: Figure 2 Applications will grow fas
Page 36 and 37: Figure 5 Evolution from multi-mode
Page 38 and 39: Operator/Provider download librarie
Page 40 and 41: Radio network subsystem - service c
Page 42 and 43: Dr. Techn. Jørgen Bach Andersen (6
Page 44 and 45: Figure 3 Two arrays with M and N el
Page 46 and 47: Figure 5 Cumulative probability dis
Page 48 and 49: Figure 8 As in Figure 5, but with F
Page 50 and 51: 48 Conclusion The challenge of prov
Page 52 and 53: 50 models are described simply by a
Page 54 and 55: 52 ping intervals or “quantizatio
Page 56 and 57: Figure 3 ASE as a function of the a
Page 58 and 59: 56 7 Conclusion and Further Researc
Page 60 and 61: Dave Wisely (39) graduated in 1982
Page 62 and 63: Figure 2 Business case study Figure
Page 64 and 65: Figure 6 BRAIN QoS architecture 62
Page 66 and 67: 64 4 BRAIN homepage. (2001, March 6
Page 68 and 69: Figure 2 The Bluetooth protocol sta
Page 72 and 73: 70 • Instant postcard: A Bluetoot
Page 74 and 75: 72 work visions come true, it is ne
Page 76 and 77: Table 1 Allocated HiperLAN bands (i
Page 78 and 79: Figure 4 Basic MAC frame structure
Page 80 and 81: 78 Preamble BCH FCH ACHs Preamble S
Page 82 and 83: throughput bit/s 80 3 2.5 2 1.5 1 0
Page 84 and 85: 82 5 References 1 CEPT. ERC Decisio
Page 86 and 87: 84 IETF Internet Engineering Task F
Page 88 and 89: Figure 2-3 Mobile IPv6 architecture
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Page 98 and 99: Figure 6 SCSs and network functiona
Page 100 and 101: Figure 9 The new business model. Fr
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Page 104 and 105: 102 Music Company Figure 3 Service
Page 106 and 107: Figure 4 OSA architecture service c
Page 108 and 109: Do van Thanh (43) obtained his MSc
Page 110 and 111: Figure 2 The first use case diagram
Page 112 and 113: 110 Box 1 - The Open Service Archit
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Page 116 and 117: Figure 10 Initiating call from PSTN
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Figure 17 A set of communication de
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120 Box 3 continued Session Descrip
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Figure 21 A laptop and peripheral d
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124 Box 4 - Bluetooth Bluetooth is
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126 6 The ICEBERG project. (2001, M
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128 new door towards the upcoming f
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? Figure 1 The Mobile Service Platf
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Figure 2 Needs and Related Services
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134 Telektronikk 1.2001
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136 Telektronikk 1.2001
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Anne Lise Lillebø (52) is Adviser
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140 with other SDOs (Standards Deve
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142 Box 2 - ETNO Declaration We, th
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Arve Meisinset (52) is Senior Resea
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146 In ITU-T we have seen needs to
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148 Each viewpoint constitutes a se
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Figure 2 UML class diagrams for tra
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152 The functionality describing th
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154 9 Potter, B et al. An introduct
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