Chapter 3: Dual-bandwidth Data Path and BOCP Design
3.1 Introduction
The focus of this thesis is on the 4G wireless mobile Internet networks to provide data
services within the overlapping areas of CDMA2000-WLAN networks. In the
overlapping area, the user’s requests are sent out through CDMA2000 networks and
the reply through WLAN networks. In order to do this, the Dual-bandwidth data path
and the Bandwidth Optimization Control Protocol (BOCP) design will be proposed in
this chapter.
This chapter will be divided into seven sections: Section 3.1 is a brief introduction
and the proposed solution of our research. In order to understand the validity of our
research, we will present a mathematical model in section 3.2. The detailed
methodology discussion of the Dual-bandwidth data path design is in section 3.3 and
the BOCP design is in section 3.4. Section 3.5 discusses the functionality of the
BOCP design. In section 3.6, we will list the performance metrics of BOCP design.
Finally, section 3.7 is our conclusions about this chapter.
3.2 Mathematical Model for the BOCP Design
The purpose of the Dual-bandwidth data path is to improve the throughput and get
higher data rates in the CDMA2000-WLAN integrated network. Cali et al. defined
and developed an analytical model [80] to calculate the integrated network throughput.
Following the analytical model, Ge et al. developed and extended multi-class model
probability p. We applying the methodology to develop and exploit our methodology
to calculate the throughput with the BOCP protocol. We assume that PDSN selects
WLAN in a slot time with a probability p as well.
As given in the multi-class model, the system throughput R can be defined as
] [ ] [ s L T B M B R= (1)
Where B[ML] is the average message length of BOCP, and B[Ts]is the average
length of virtual selection time, which is defined as the interval time between two
successful selection as shown in Figure 3-1.
Figure 3-1: A virtual selection time
Following the Figure-1, the expression of B[Ts]is derived in (2) and (3) as
] [ ] [ ] [ ]
[T Bidletime B collisiontime B successfultime
B s = + + (2)
Where B[[idletime] is the average consecutive idle time; B[collisiontime]is the
average time that the channel is busy due to a collision; B[successfultime] is the
average time required to complete a successful selection.
that there are Nc[B] time collisions in a virtual selection time. The case has been
shown in the Figure 3-2.
Figure 3-2: Virtual selection time
Following the methodology, the B[Ts]can be expressed as
] [ ] [ ] [ ) 1 ] [ ]( [ ]
[T Bidletime N B Bcollisiontime N B B successfultime
B s = c + + c + (3)
Considering WLAN system and CDMA2000 system in which there are M traffic
classes and ni(i = 1,2,...,M) stations for class-i traffic, the derivation of total number
of Nc[B]for the multi-class traffic can be founded in [81] shown as follows:
1 ] ) 1 ( ) 1 ( [ ) 1 ( 1 ] [ 1 1, 1 1 − − − − − =
∑
∏
∏
= = ≠ − = M i N j M i j j N i i i M i N i c j i i p p p N p B N (4)We assume that an idle time slot isTidletime and a collision time isTcollisiontime, then
theB[idletime] and B[collisiontime]can be found in the [81] as follows:
idletime M i N i M i N i T p p idletime B i i . ) 1 ( 1 ) 1 ( ] [ 1 1
∏
∏
= = − − − = (5) ime collisiont M i N i M i N i T p p ime collisiont B i i . ) 1 ( 1 ) 1 ( ] [ 1 1∏
∏
= = − − − = (6)Where we assume that piis the selection probability for WLAN stations and
j
We applying the formula (4), (5) and (6) in to the formula (3) , then we can get
] [Ts
B . Following the methodology, we applying formula (3) in to formula (1), the
throughput R can be expressed as follows:
] [ ] [ s WLAN L WLAN T B M B R = − (7) ] [ ] [ s CDMA L CDMA T B M B R = − (8)
From the two formulas (7) and (8) above, the throughput ration between WLAN
and CDMA traffic can be calculated as follows:
) 1 ( ) 1 ( * ] [ ] [ ] [ ] [ / ] [ ] [ i j j i CDMA L WLAN L s CDMA L s WLAN L CDMA ELAN p P p p M B M B T B M B T B M B R R r − − = = = − − − − (9)
From the two formulas (5) and (6) above, the ration of B[[idletime]and
] [collisiontime
B can be calculated as follows:
] [ ] [ ime collisiont B idletime B =
λ
= ] [ * * ) 1 ( 1 ) 1 ( * ) 1 ( 1 ) 1 ( * ) 1 1 ] ) 1 ( ) 1 ( [ ) 1 ( 1 ( 1 1 1 1 1 1, 1 1 me collsionti B T p p T p p p p p N p idletime M i N i M i N i idletime M i N i M i N i M i M i j j N j N i i i N M i i i i i i j ii ii∏
∏
∏
∏
∑
∏
∏
= = = = = = ≠ − = − − − − − − + − − − − − = me collsionti idletime M i N i M i N i M i M i j j N j N i i i M i N i B T p p p p p N p i i j i i * ) 1 ( ) 1 ( 1 * ] ) 1 ( ) 1 ( ([ ) 1 ( 1 1 1 1, 1 1∏
∏
∑
∏
∏
= = = = ≠ − = − − − − − − = me collisonti idletime M i M i N j N i i i M i N i B T p p p N p i i i * ] ) 1 ( ) 1 ( [ ) 1 ( 1 1 1 1∑
∏
∏
= = = − − − − = me collisonti idletime M i N i i i M i N i M i N i B T p p N p p i i i * ) 1 ( ) 1 ( ) 1 ( 1 1 1 1 1∑
∏
∏
= = = − − − − − (10)In the formula (10) above, the
∏
∏
∏
∏
= = = = + − − = − − = − − − M i M j N i i N i M i N i M i N i i j i i p p j i f p p p 1 1 1 1 1] 1 1 ) , ( [ 1 ) 1 1 ( ) 1 ( ) 1 ( 1 =∑
=∑
=∑
= − − + − M j M j i i M j j i i j p p j i f N j i f p p N j i f 1 1 2 2 2 1 (, ) ) ( , ) ]*(1 ) [( * 2 1 1 * ) , ( (11)Where f(i, j) is a factor between the i and j. we applying Taylor formula and then
get the formula (11) above. Now let x= pi (1−pi) , =
∑
M=j f i j Nj b 1 (, ) ,
∑
= −∑
= = M j M j j j f i j N N j i f a 1 1 2 2 ] ) , ( ) ) , ( [( * 2 1 and =∏
M= − i N i i p d 1(1 ) . The formula (11) can be rewrite as 0 1 2 + − − = d d bx ax (12)From the formula (12) above, a≠0
0 ) 1 ( 4 ) 1 ( * * 4 4 2 2 2 − = − − − = + − ≥ = ∆ d d a b d d a b ac b (13)
Therefore, there are real roots for the formula (12). Since x= pi (1−pi) and p
is the selection probability for WLAN, the formula (12) and (13) shows that the
model can select WLAN for transmission.
3.3 Dual-bandwidth Data Path Design
The Dual-bandwidth data path is designed to get higher data rates and utilize the two
network resources. Since no single network can provide the mobile users fast speed
and wide coverage, it is necessary for 4G wireless mobile Internet networks to
integrate current existing networks. However, this kind of integration can be based on
any two overlapping network areas. When a mobile node comes into the overlapping
area, both networks can provide services for the mobile node simultaneously. In our
and reply can be received from the other network (i.e. WLAN).
3.3.1 Dual-bandwidth Data Path Model
In order to design Dual-bandwidth data path, we issue the model. The model design is
based on WLAN and CDMA2000 two networks overlapping area. When a mobile
node comes into the overlapping area, WLAN and CDMA2000 networks are serving
for the mobile node simultaneously. Data requests are sent from CDMA2000 network,
and replies are received from WLAN network (see Figure 3-3).
In this model, the MN request goes through the first connection (MN → BS →
PDSN → CN) and the resulting reply comes from the second connection (CN →
PDSN → AP → MN). Thus, two networks provide services for the mobile node
simultaneously.
Figure 3-3: Dual-bandwidth Data Path Model
3.3.2 Dual-bandwidth Data Path Design
The components of the Dual-bandwidth data path implementation are shown in Figure
3-4. There are four components which are bandwidth management, bandwidth
selection, packet receiver and bandwidth monitor. The function of bandwidth
HA CN
PDSN
AP BS
management is to install and delete bandwidth monitor components dynamically
when it receives indication messages. The bandwidth management is located at both
ends i.e. the sender and the receiver. On each path, there is one bandwidth monitor
installed. The function of bandwidth monitor is to monitor the available bandwidth
and calculate the proper transmission rates on the corresponding path. The current
existing path is informed by the bandwidth management after installing/deleting each
bandwidth monitor. The bandwidth monitor will provide the rates information when it
receives the current existing path information from bandwidth management. The
function of the bandwidth selection is to calculate and report encoding rates to
encoder, and then applications will be encoded to appropriate paths. The packets
receiver accepts incoming packets from the bandwidth monitor, filters and reorders
them before sending them to the decoder. A detailed description on each of these four
modules is given in the following sub-sections.
3.3.2.1 Bandwidth Management
Our Dual-bandwidth data path implementation is based on the WLAN and
CDMA2000 networks. WLAN network is implemented to cover small area, whereas
CDMA2000 network is implemented to cover wide area. Both of them have different
bandwidth, data rates and cost. Therefore, bandwidth management component is
needed for implementing bandwidth selection in the Dual-bandwidth data path
architecture. During the bandwidth selection, the bandwidth management will
perform the following two operations:
bandwidth path, and then it sends a RATE_READY message to the local
sender/receiver to indicate the existence of new bandwidth when mobile IP reports a
new location with PATH_ADD message;
Figure 3-4: Dual-bandwidth Data Path
The bandwidth management will delete the bandwidth monitor and send a
RATE_DEL message to the local sender/receiver to indicate that an existing
bandwidth is lost when the mobile IP reports a loss of new location with PATH_LOSS
message.
Both types of bandwidth indication messages (i.e RATE_READY and
RATE_DEL) contain a unique PATH_ID to identify the bandwidth to a mobile node.
simultaneous binding and route optimization options are used.
3.3.2.2 Bandwidth Selection
Bandwidth selection is only located at the sender side. Since WLAN has been
integrated into CDMA2000 networks, the message exchange is needed between both
networks. In this case, the bandwidth selection calculates and reports the encoding
rates to the encoder so that it can adapt its encoding rates accordingly after the
bandwidth selection receives the bandwidth existence information from the bandwidth
management and the rate information from the bandwidth monitor. The bandwidth
selection is also responsible for assigning bandwidth encoded application.
3.3.2.3 Bandwidth Monitor
We have stated earlier that the function of bandwidth monitor is to calculate the
proper transmission rates and monitor packet flows on the corresponding path. The
bandwidth monitor is located at both the sender and the receiver on each bandwidth
path which is installed by the bandwidth management. The sender and the receiver
reports are exchanged between the sender and the receiver. In this case, the sender
generates a report to update the rate control information and the receiver generates a
report for the controlled path in order to observe congestion status to the sender. The
rate control information of the report includes the path ID so that it can be directed to
the corresponding bandwidth monitor.
3.3.2.4 Packets Receiver
is to buffer and reorder all the packets received from both bandwidth monitor. It is
also responsible to filter out the redundant packets before delivering them to the target
application.
In order to establish and manage the Dual-bandwidth data path, we propose
Bandwidth Optimization Control Protocol (BOCP) which will be discussed in the
following section.
3.4 Bandwidth Optimization Control Protocol Design
Designing the bandwidth optimization control protocol is a challenging task due to the
following factors:
• Mobile Internet protocol is a basic protocol running on the future 4G wireless
mobile Internet networks. The mobile IP assigns IP address on mobile nodes
according to its location information, which related with location management,
and the bandwidth optimization control protocol design is based on two
network bandwidth utilization. This is very difficulty to math the current
mobile Internet protocol; and
• Dual-bandwidth data path for 4G wireless mobile Internet works is based on
the integration of WLAN-CDMA2000 network resources. To establish a data
connection between the two networks, the bandwidth optimization control
protocol design is a big challenge.
In order to establish the Dual-bandwidth data path, we propose the bandwidth
optimization control protocol whose design is based on both the location management
The current existing location information management techniques can be
classified into two categories:
• Network layer management techniques; and
• Transport layer management techniques.
The main objective of most of the network layer location management
techniques was to reduce re-routing packet loss. The transport layer location
management techniques were proposed to get reliable data transmission. Both the
network layer management techniques and transport layer management techniques are
not involved in the bandwidth utilization under the integration of WLAN-CDMA2000
networks.
WLAN is operating in 2.4GHz frequency band which can support a maximum
data rate of 11Mb/s or 54Mb/s about its standard 802.11b and 802.11g respectively
[82]. As local area coverage, WLAN technologies can achieve a higher data rate at a
very low cost and therefore are now widely implemented in hotels, restaurants,
shopping malls, homes etc. On the other hand, for a wide area coverage, the
CDMA2000 network is widely implemented but with moderate data rate. These two
networks are incompatible but allowing these networks to complement each other is
an added advantage. Possible solution that we have proposed is to optimize the
network resource usage by allowing mobile devices full access to both networks
simultaneously. According to Lucent research result, it is found that the Internet
characteristics in bandwidth utilization that relates to request amounts to one fourth of
is to allow mobile node sending request through CDMA2000 network and getting
reply from WLAN network by Dual-bandwidth data path. The bandwidth
optimization control protocol design is to establish the Dual-bandwidth data path,
which is based on the integrated architecture of CDMA2000-WLAN networks as
presented in Figure 3-5.
3GPP2, a standard organization has issued the integrated architecture of WLAN
and CDMA2000 networks, in which a new component has been added in. The new
component, Packet Data Interworking Function (PDIF) is between the access point
and the Internet networks [64]. The functions of the PDIF have been specified as
following:
• Security gateway;
• IP connectivity;
• User authentication;
• Secure tunnel management;
• Policy Enforcement; and
• Accounting
Two of the PDIF functions i.e. the IP connectivity and user authentication related
with our research. The bandwidth optimization control protocol is designed to use the
PDIF functions to manage the Dual-bandwidth. In the case, the application requests
will be managed by PCF (Packets Control Function) in CDMA2000 network and the
reply will be controlled by PDIF in WLAN network. The bandwidth connection is
AP MN2 MN1 MN3 PCF MSC/VLR PDSN AAA HA HLR PSTN INTERNET MN4 BS PDIF
Figure 3-5: CDMA2000-WLAN Convergence Network Architecture [64]
The bandwidth optimization control protocol (BOCP) is implemented in between
MAC layer and TCP/IP layer. An illustrative example of the functionality of BOCP
consisting of BOC (Bandwidth Optimization Control) and BOCA (Bandwidth
Optimization Control Agent) components is presented in Figure 3-6. Packets received
from higher layer are aggregated to BOC. The BOC is defined to response for
generating, sending out and receiving BOCP messages and subsequently using
received updates to update the relevant routing tables in our simulation model. The
BOCA is a component which holds information about direct link interfaces of one
node and interfaces of other nodes associated with the BOCP.
BOC and BOCA components. Thus, the basic design choices are below:
• When and where to perform packets assignment;
• Which packets are selected for assignment.
TCP(UDP)/IP Asyncoronous Data/Application D a ta L in k L a y e r M A C S u b L a y e r P L C P S u b la y e r P M D S u b la y e r P h y s ic a l L a y e r Interface (BOC/BOCA)
Figure 3-6: BOCP Overview
3.5 Functionality of the BOCP Design
3.5.1 BOCP Packets Selection and Assignment
Figure 3-7 illustrates the processing of packets from the network layer to data link
layer for transmission. The processing includes packets selection and assignment.
In the BOCP, we consider that the selection of packets is in strict order received
from network layer. Packets from the network layer are enqueued in order. First in
iterative operation that will first select the packet at the head of the queue for
transmission preparation. Then the next packet in the queue will be selected. If the
destination address of the packet is the same as the destination address of the current
working frame, the packet is aggregated with the current set. This selection process
iterates until condition is false. The aggregated collection of packets is then
encapsulated into the WLAN frame for transmission.
Figure 3-7: Network Layer and Data Link Layer for BOCP
After the packet is selected, it will be queued to interface for sending out. In the
Figure 3-7, it shows that the BOCA has a direct link interface which is used to send
BOCP messages after the messages generated by BOC. The BOCP messages will be
interfaces and their direct neighbors so that it can generate a correct BOCP message.
Any packets that need to be sent out will be generated by the BOC. In addition, the
BOC will also received BOCP messages and subsequently using received updates to
update relevant routing tables. Thus, the necessary BOCP messages are generated by
BOC, and then dispatched them to a correct destination.
3.5.2 BOCP Definition and Assumption
The BOCP is implemented using Java Network Simulator (ns2 java version) [84]. The
Java Network Simulator (JNS) allows developer of networking protocols to simulate
their protocols in a controlled environment. Several assumptions are necessary to limit
the scope of our research. The intent of these limiting assumptions is to keep the
simulation complexity manageable, while still meeting the research goals.
The focus of this research is the 4G wireless mobile Internet to provide data
services inside the integrated CDMA2000-WLAN network. Therefore, the voice
service, circuit switched domain shown in the Figure 3-5 is not considered. Thus, the
main system components of the CDMA2000-WLAN packet domain architecture are
remodeled as in Figure 3-8. The architecture consists of the mobile node (MN), the
base station (BS), the packet control function (PCF), the Packet data service node
(PDSN), the access point (AP), and the packet data interworking function (PDIF).
The mobile node can be a handset, a laptop, a personal digital assistant, etc. We
assume that these devices can have full TCP/IP protocol support with data and
multimedia application running.
The base station (BS) and the access point (AP) provide radio interface and radio
link management functionality for the mobile node. These devices provide
connectivity to packet control function (PCF) and packet data interworking function
(PDIF) respectively.
The packet data service node (PDSN) provides IP interface to the Internet. For
session management and radio resource management, we assume that the CDMA2000
connection is already established under the overlapping area, and the WLAN radio
resource is available for setting up a new connection.
3.5.3 BOCP Association
The BOCP association is initiated between the mobile node and the base station or the
access point. Certain BOCP frame is used to initiate the BOCP association. The
conforms to IEEE 802.11 requirements [53]. Within the MAC Header, the first two
octets define Frame Control (FC) field as shown in Figure 2-6 802.11 frame structure.
The Frame Control field consists of the following subfields: Protocol Version, Type,
Subtype, To DS, From DS, More Fragments, Retry, Power Management, More Data,
Wired Equivalent Privacy (WEP), and Order. The format of the Frame Control Field
is illustrated in Figure 3-9. B0 B1 B2 B3 B4 B7 B8 B9 B10 B11 B12 B13 B14 B15 Protocol Version Type Subtype To DS From DS More Frag
Retry Pwr Mgt More Data WEP Order
Figure 3-9: IEEE802.11 Frame Control Field [53]
Within the Frame Control Field, there are Type and Subtype subfields. The Type
field is 2 bits in length, and the Subtype field is 4 bits in length. The Type and
Subtype fields together identify the function of the frame. There are three frame types:
control, data, and management frames. Each of the frame types has several defined
subtypes.
In the MAC header, as shown in Figure 2-8 802.11 Frame Structure and Figure
3-9 802.11 Frame Control Field, the following items are related specifically to our
BOCP protocol:
• Type/Subtype field: Type/Subtype fields will be used to indicate that this
frame is a BOCP frame. The type field will be set to the previously reserved
value (11), and the subtype (0000-1111) will be used to indicate any of the
accepted data frames;
• Duration/ID field: Immediately following the Frame Control field in the
also 16 bits in length. The contents of this field that relates to our research are
as follows:
o In the subtype frames, the Duration/ID field carries the association identity
(AID) of the station that transmitted the frame in the 14 least significant bits
(lsb), with the 2 most significant bits (msb) both set to 1. The value of the
AID is in the range of 1 to 2007;
o In all other frames, the Duration/ID field contains a duration value as defined
for each frame type. For frames transmitted during the contention-free period
(CFP), the duration field is set to 32768.
• Frame Check Sequence (FCS): FCS will be computed over the entire
aggregate header.
Therefore, we assume that during association between the PDIF and AP, it is
necessary for an association request frame to support our BOCP enhancement by
setting the first 5 bits (i.e. bit from B0 to B4) of the capability information field shown
in Figure 3-10.
This frame is transmitted by the PDIF to AP in order to initiate association. The
AP will respond with an association response frame. The AP will use the same first 5
bits in the capability information field to declare its ability to support the BOCP.
B0 B1 B2 B3 B4 B5-B15
ESS IBSS CF Poll able CF Poll request Privacy Reserved Octets: 2
3.5.4 BOCP Frame Format
The BOCP frame format is shown in Figure 3-11. The following items are specific to
our BOCP:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 command (1) version (1) Routing Domain (2)
Address Family Identifier (2) Route Tag (2) IP Address (4)
Subnet Mask (4) Next Nod (4)
Metric (4)
Figure 3-11: Format of BOCP message [53]
• Command field defined message type and subtype of request or response.
Type/Subtype fields explained earlier will be used to indicate that this frame is
a BOCP frame;
• Routing Domain field will be used to indicate that mobile nodes of one routing
process can be located in both WLAN and CDMA2000 domains; and
• Next Nod field is set to IP address of the next node along the way. As we have
presented in section 3.2, the necessary BOCP messages are generated from all
nodes to all their neighbors. Therefore, this field is used to indicate the mobile
node neighbor’s IP address.
The other frame fields are used to indicate the same functionality as explained in [53]:
i. Version is set to be 2;
ii. Address Family Identifier for Internet networks is always 2 for IP; 20 bytes
iii. Route Tag provides support for EGPs;
iv. Subnet Mask indicates the destination subnet mask (all 1’s for host
address); and
v. Metric will be used to count node number of the special routing.
3.6 Performance Metrics on BOCP Design
The BOCP is evaluated based upon throughput and buffer requirement. Therefore, the
throughput and buffer requirement are two main metrics for evaluating the BOCP
performance. The two metrics are defined as follows:
3.6.1 Throughput
The CDMA2000 network and WLAN are two different networks with different
technologies and bandwidth. The WLAN bandwidth is much wider than CDMA2000
network. Regarding the bandwidth disparity, we establish the Dual-bandwidth data
path for utilizing the two network resources to get higher throughput by implementing
the BOCP. Thus, throughput can be used to evaluate the performance of this
integration. In communication networks, throughput is the amount of digital data per
time unit that is delivered over a physical or logical link, or that is passing through a
certain network node. For example, it may be the amount of data that is delivered to a
CDMA2000 network mobile node or a WLAN network mobile node, or between the
two mobile nodes. The throughput is usually measured in bits per second (bits/s or
bps) and occasionally in data packets per second. Relative to our research, throughput
The data packets received at the physical layer are sent to the higher layer if they are
destined. We measured this value in terms of bits per second. Throughput represents
an average rate of traffic flow where higher values are better.
3.6.2 Buffer Requirement
As we have shown in Figure 3-4, the Dual-bandwidth data path was proposed and the
buffers are required for the Dual-bandwidth data path. According to ITU
(International Telecommunication Unit) standards, for a non-real-time Internet session,
the buffer time,Bt, is defined as the length of time that the packets are released from
the existing route to a new route which is established and this is calculated as follows
[85]: ) , （C N MN t t
R
B
=
(1)During the course of the establishing the Dual-bandwidth data path, the
application packets were transmitting from CN to MN, using any two nodes distances
by the packets rate to calculate the buffer time for the mobile IP packets which is from
CN to MN. In the formula above, one can denote the buffer time as
) , (CN MN t
R
which is shown in (1). This represents the time that the controlled-loadtraffic is buffered by CN. Then, the required buffer size,
B
s , is calculated as follows:r t s
B
P
B
=
*
(2) s r rb
P
P
=
*
(3)From the formula, the buffer size (Bs) is equal to buffer time (Bt) times with
packet rate (Pr), and the packet rate (Pr) is equal to bit rate (br) times with the
s r t
s
B
b
P
B
=
*
*
(4)3.6.3 BOCP Evaluation Techniques
Generally, there are three possible techniques of performance evaluation used in
research, which are analytic, simulation, and measurement [86]. The selection of a
particular evaluation technique depends on whether it can significantly impact the
outcome of a performance evaluation. These methods differ in terms of accuracy, cost,
and required time. We choose simulation to conduct this performance analysis due to
limitations in available resources.
3.6.4 BOCP Simulation Parameters
We have developed a simulation environment to evaluate our proposed architecture.
Simulation parameters for our simulation model are based on the values that
accurately modeled the architecture proposed by 3GPP2. These simulation matrices
Simulation
Parameters Descriptions Values
PDIF
Functionality
This value specified whether the Packet Data Interworking Function is enabled for the WLAN
MAC. Enabled
AP Functionality
This value specified whether the access point is
enabled for the WLAN-MAC. Enabled WLAN Physical
Layer
Characteristics
The value of this attribute determined the physical layer technology in use.
Direct Sequence
WLAN Data Rate
This value specified the data rate that is used by the MAC for the transmission of the data frames
via the physical layer. 11Mbps CDMA2000
1x-EVDO Cell State
This value indicated that all CDMA2000 1x-EVDO uplink and downlink traffic is sent on data control
channels (DCCH). DCCH
Table 3-1: BOCP Simulation Matrices
3.6.4.1 PDIF Functionality
3GPP2 has specified the functionalities of packet data interworking function (PDIF).
These functionalities have been presented earlier in this chapter. This value specified
whether the Packet Data Interworking Function is enabled for the WLAN-MAC.
3.6.4.2 AP Functionality
WLAN access point is a general component in its network which is used to assign
user request and reply. This value specified whether the access point is enabled for the
WLAN-MAC [53].
3.6.4.3 WLAN Physical Layer Characteristics
Sequence Spread Spectrum (DSSS). The value of this attribute determined the
physical layer technology in use.
3.6.4.4 WLAN Data Rate
Following the IEEE 802.11b standards, we set WLAN data rate to 11 Mbps. This
value specified the data rate that is used by the MAC for the transmission of the data
frames via the physical layer.
3.6.4.5 CDMA2000 1x-EVDO
Qualcomm’s proprietary HDR (High Data Rates) technology dedicates a 1x carrier for
fast data use only. This is called 1xEV DO (Data Only). CDMA2000 1xEV-DO is
specified in 2001 by 3GPP2, which introduces a new air interface and supports high
data rates service for downlink [64]. It requires a separate 1.25 MHz carrier for data
only, but the speed can be up to 3.1 Mbps on the downlink. Data transmission on
supplemental channel is supported. This value sets for the simulation parameter
indicates that all CDMA2000 1x-EVDO uplink and downlink traffic are sent on the
data control channels (DCCH).
3.6.5 BOCP Simulation Scenario
The simulation is running under the scenario termed a dual mode mobile node access
CDMA2000-WLAN convergence architecture of 3GPP2. The simulation model of the
Figure 3-12: Simulation Scenario Model
The primary focus of the scenario is the two access network used simultaneously
for the mobile node. When the mobile node comes into the WLAN overlapping region
from the CDMA2000 coverage area, the MN request will go through the first
connection (MN → BS→ PCF→ PDSN → CN) and the resulting reply will come
through the second connection (CN →PDSN→ PDIF → AP→ MN). The scenario
simulated a mobile node running the BOCP on the integrated CDMA-WLAN network.
The purpose of the simulation is to exercise the integrated system over the new
protocol to demonstrate system data rates.
3.6.6 BOCP Simulation Design
The rationale and the overview of the simulation-based experiments employed to
evaluate the BOCP enhancement will be discussed in this section. The results and
JNS standard models and modified them to support our BOCP. The main classes such
as BOC class, BOCA class, BOCPMessage class, MobileNode Class, Route Class and
RoutingTable class are designed as following. Other supported classes such as
QueueList class, RouteAlreadyInRoutingTableException class, etc. are not listed but
can be found in attachment.
3.6.6.1 BOC Class
The BOC class is responsible for generating BOCP messages and sending them to the
correct destinations. It is also responsible for receiving the updates and using them to
update the relevant routing table.
At this stage it is necessary to take the decision of whether to have a global
(static) BOC class. The global BOC class would be responsible for sending out
updates from nodes and updating the routing tables of all the nodes in the simulation
network. The BOC class activity diagram is presented in Figure 3-13 where it shows
that the BOC class generates BOCPMessages for all node interfaces. The
BOCPMessages will be used to update appropriate routing tables. Once all the
BOCPMessages have been sent out and all the routing tables have been updated, the
BOC class will place a new command in the simulator queue for stopping or
continuing the activity.
The BOC class will accomplish its tasks by making use of the global information
3.6.6.2 BOCA Class
In the simulation network, we are interested with the direct link information since in
BOCP a mobile node will need to send data to its direct link neighbor only. Hence it is
necessary to have a list of node interfaces and their direct neighbors in order to
generate the correct BOCP routing update messages. Therefore, the BOCA class
needs to have information about the interfaces associated with a particular node and
keep track of what is linked to what in the simulation network (see Figure 3-14).
Figure 3-14 shows the BOCA class hash table. The index of the array
represents the interface of a node and it will be stored in the hash table i.e. given a
router interface, one could retrieve from the hash table the index of the array which
contains links to that interface.
From the BOCA class hash table, a reference to a vector will be stored at that
index and this second-dimensional vector will hold all the interfaces that the router
interface is directly linked to. An array has been chosen for the first dimension
because once a network has been set up it will not be necessary to add new nodes very
often. In fact, in the simulator program at present, once a network has been set up and
the simulation starts, it is not possible to add new nodes to the network.
In the hash table, the information about the interfaces associated with particular
nodes will be stored as a mobile nodes object. The BOCA class has a Vector
containing references to the mobile node object. The mobile node object will then be
occurred as instance variables in the BOCA class.
time and therefore be more efficient. In order to reduce the retrieve time, the data
retrieved from the hash table need not to check table items one by one. It needs to
check the node interface 1 and then for the node interface 2 in the hash table.
Figure 3-14: The BOCA Class Hash Table
3.6.6.3 BOCPMessage Class
The BOCPMessage holds the necessary information to update a MobileNode’s
routing table according to BOCP. The class contains main information as following:
• The first is a MobileNode interface from and to which this BOCPMessage will
be sent;
• The second is the simulator time of this updated; and
• The third is vector contains BOCPMessage object references.
The functionality of this class is to define what will be sent from a certain
Route that will be chosen to be sent to that particular neighbor.
After the BOCPMessage verified its route, then the route can reach destination. A
Vector as a linear data structure is suitable to hold the Route objects. We created the
class of RouteAlreadyInRoutingTable to deal with this.
3.6.6.4 MobileNodes Class
The MobileNode class contains a node and the interfaces associated with that node.
The BOC class has a vector as an instance variable which contains references to the
MobileNode object.
3.6.6.5 Route Class
The Route class holds information about which interface to send packets out for a
particular destination together with the IP addresses of its neighbors. This class will be
modeled on the pre-existing Route class found in JNS, but will require some
modification for compatibility with BOCP.
3.6.6.6 RoutingTable Class
The RoutingTable class is used to store the route objects. This class is modeled on the
pre-existing RoutingTable class from JNS. The data structure of the class is hash table
(see Figure 3-14). This would be more efficient when updating routes since it is not
needed to go through the whole routes looking for the one for updates.
3.7 Conclusions
CDMA2000 and WLAN networks. In order to establish the Dual-bandwidth data path
between the two networks under the integrated architecture of CDMA2000-WLAN,
we proposed the Bandwidth Optimization Control Protocol.
BOCP is designed for the Dual-bandwidth data path. Data transmission on the
Dual-bandwidth data path is controlled and managed by the BOCP. Thus, this chapter
proposed two designs, the Dual-bandwidth data path design and the BOCP design.
In order to design BOCP, we have defined the functionalities of the BOCP
including the BOCP packets selection and assignment, the BOCP packet definition
and assumption, the BOCP association and the BOCP frame format.
The performance metrics on BOCP design has been defined which are including
the BOCP evaluation techniques, the BOCP simulation parameters, the BOCP
simulation scenario and the BOCP simulation design.
In order to prove the Dual-bandwidth data path and BOCP design, the system
